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THE hydrogen ion cencentration varies from one portion of the intestine to the next, depending to some extent on certain variables; the more obvious being the type of material collected for analysis i.e. collected ingesta as opposed to intestinal tract scrapings. Variability will depend also on time elapsed after feeding and type of electrode used. Generally, the pH scale from the crop to the cloaca (Sturkie, 1954) is considered to be on the acid side. The literature contains several reports of the influence of diet on the gastrointestinal pH. Neff (1931) reported that lactic acid, mineral oil and water lowered the pH of the excretory products. The terminal portion of the duodenum is reported acidic due to the presence of amino and fatty acids (Shaw, 1913). However, there is considerable literature (Mussehl, Blish and Ackerson, 1933; Heller and Penquite, 1936; and others) which would indicate that the type of diet …

THE site of shell mineralization in the bird has been established to be the oviduct shell gland or uterus. Eggs laid via a fistula posterior to the shell gland are completely calcified, whereas those laid via a fistula anterior to this organ lack shell mineralization; partial resection of the shell gland leads to a proportionate decrease in the quantity of mineral deposited in the shell (Asmundson and Jervis, 1933). Richardson (1935) has shown that the shell gland epithelium does not appear to function as a calcium storage organ. He attributes the calcium excretion associated with shell formation to increased circulation in the shell gland in conjunction with the increased calcium concentration of the circulating blood. However, a thickening of the surface layer of the shell gland cells was observed during shell formation, indicating some associated tissue changes. Descriptions of the shell gland structure are available (Bradley and Grahame, 1950; Romanoff . . .

ANATOMICAL and embryological relationships between the pineal and diencephalon and between the pituitary and the diencephalon have been evaluated in detail for many different animals (Gladstone and Wakeley, 1940; Ariens Kappers and Schade, 1965). Recently Owman (1964) described certain physiological functions in the rat pineal, and Quay (1965) summarized the structural and cytological differences between the avian and mammalian pineal organ. Pineal extracts have successfully decreased castrate-pituitary-hypertrophy in the male chicken (Shellabarger, 1952). Rowan's (1926) classical work with the slate-colored junco focused attention on the influence of light on neuroendocrine mechanisms. Farner (1964) has reviewed the photoperiodic control of the bird's reproductive cycle, and the relationship between light, hypothalamus, and adenohypophysis has been reviewed by Bullough (1959), Donovan and Harris (1955), and Hague (1964). Histochemical studies of the pineal gland indicate acid and alkaline phosphatase as well as other enzyme systems to be present in the pineals of the pig,…

Both male and female chickens were injected with a dose of selenomethionine-75 Se two hours before killing and the total selenium and the radioactivity in various tissues were determined. For the sexes the tissues can be ranked as follows for total selenium content/gm. fresh tissue: (males) pituitary, pineal, adrenals, kidneys, liver, spleen, pancreas, retina, diencephalon, blood, cerebrum, testes, cerebellum and pectoral muscle; (females) pituitary, pineal, adrenals, kidneys, diencephalon, spleen, pancreas, liver, oviduct, cerebellum, ovary, cerebrum, pectoral muscle and blood. The specific activity of 75 Se was highest in testes, pancreas, liver, kidneys and spleen of males; and pancreas, oviduct, blood, kidneys and liver of females. About 82% of the radioactivity was associated with a T.C.A. insoluble fraction in liver.

IN A previous report (Smith et al., 1957), the weight of the oviduct in the normal laying hen was compared with the secretory state of the magnum, as estimated by the position and condition of eggs found in the oviduct on autopsy. The oviduct was considered “pre-secretory” if it contained a hard-shelled uterine egg since these birds, if not sacrificed, soon would have deposited albumen on a new egg; it was considered “post-secretory” when a soft-shelled uterine or isthmian eggs were found. Assuming that albumen is accumulated in the magnum during the intersecretory period (as is indicated by histological findings; Richardson, 1935), one would expect the weight of the “pre-secretory” oviduct to exceed that of the “post-secretory” oviduct by approximately the weight of the deposited albumen (i.e., 20 gms.). Since this anticipated difference in oviduct weight was not found (Smith et al., 1957), another experiment, reported herein, was carried out …

THE distribution of labeled materials in the animal body at various times after their administration can be used to determine the pathways involved in the metabolism of those materials. Quite a few studies have been made of the distribution of radiophosphate (P32) in various animals, the earlier work having been reviewed by Hevesy (1948). Recent studies have been made on the distribution of ingested radiophosphate in laying hens (Shirley et al., 1951) and on the distribution of parenterally administered radiophosphate in laying hens (Shirley et al., 1954), in rats (Rosenfeld and Beath, 1952), in swine (Smith et al., 1951), and sheep (Smith et al., 1952). Although the mode of injection in these latter studies varied (viz., intramuscular, intravenous, or intraperitoneal), the mixing rate of circulating and interstitial fluids is so rapid (Kleiber et al., 1950) that they are equivalent at the sampling times involved (hours or days). Distribution studies following …

THE hen’s egg contains a large amount of phosphorus (about 0.6% of the dry matter) which is distributed in various chemical forms through its three principal components: shell, white, and yolk. It has been observed that radioactive phosphate when administered (fed or injected) to a laying hen appears rapidly in all components and phosphorus compounds of the egg (Chargaff, 1942; Hevesy and Hahn, 1938; Lorenz et al., 1943; O’Neil et al., 1948). The effect of environmental factors on egg production and egg composition (Smith et al., 1954) may well be associated with changes in the rate and extent of transfer of phosphorus from the hen to the egg. This paper reports the results of some studies on the deposition of injected P32 in the egg which were carried out under controlled conditions. METHOD The environmental conditions, a description of the experimental animals, and general methods of analysis used in this …

DURING egg formation, large quantities of calcium are deposited as carbonate on the developing shell. The site of shell formation, the oviduct shell gland, is not a calcium storage organ; consequently, calcium must be mobilized rapidly from body stores to meet the periodic requirements of shell formation. Since the body calcium is located almost entirely in osseous tissue, it must pass through the circulatory system in rather large quantities during each period of active shell formation (about 14 hours; Bradfield, 1951). There is also an increase in calcium absorption from the gut during shell formation (Buckner et al., 1930), which contributes to the fluctuation in blood calcium concentration. The literature contains several reports of the influence of shell formation on blood calcium. Charles and Hogben (1933) found that plasma calcium concentration during egg formation was about 20% higher than during non-laying periods. However, their data for hens with a forming . . .

THE existence of extra-retinal photoreceptors in the brain has been suggested by numerous workers, e.g., Oishi et al. (1966) and Menaker (1968). However, microscopic examination of the pineal and of the brain reveal no pigmented photoreceptors. The suggestion that retinal selenium may have an important role as a photon receptor and energy transformer (Aberg, 1966) suggested to us that other neural areas may be high in selenium. Present technological application of the element in photocells appear to involve only the elemental forms, and it was thought that a general survey of tissues for selenium concentrations without regard to oxidation-reduction status might provide a starting point for an investigation of a possible role of the element in certain aspects of avian physiology. This is a report on the relative distribution of selenium in not only the pineal but also in other avian tissues. Although toxic aspects of excess selenium in animal…

The bound, or nondiffusible, calcium component of laying hen's plasma was found to be freely dissociable, in conformance with the mass action principle. No evidence of enzymatic activity, which would dissociate the complex, was found in various tissues and materials associated with shell formation. The kinetics of dissociation of the calcium-protein complex were studied in a series of plasma preparations in which the calcium concentration alone was varied. The dissociation constant for the calcium-protein complex of laying hen's plasma was found to be 10–1.1. Also investigated was the effect of changes in salt concentration (NaCl) and pH on the dissociation of calcium-proteinate.

Domestic fowl exposed to chronic acceleration (prolonged centrifugation) do not appear to “habituate” to repeated rotatory stimulation, as do similarly treated birds maintained at normal gravity. Chronically accelerated birds frequently exhibit postural or locomotor abnormalities, and such individuals lack a nystagmic response to rotatory stimulation. Submitted on August 21, 1961

To test whether there is a circadian rhythm in the ACTH response to stress, young female rats were exposed to a variety of ACTH-releasing stimuli at 0600 and 1800 h and changes in circulating ACTH and corticosterone were measured. The results of these experiments suggested that after the high intensity stimuli of laparotomy with intestinal traction or 250 mug histamine ip/100 g BW, the morning ACTH response was greater than the evening response. However, the ACTH response to ip saline was greater in the evening in one experiment and greater in the morning in a second experiment. Plasma corticosterone responses were faster and greater in the morning in the first experiment and in the evening in the second experiment. The ACTH response to 125 mug histamine ip/100 g BW was greater in the evening and the change in corticosterone was greater in the morning. Thus, after low intensity stimuli, the ACTH responses appeared to depend on both the lag time prior to the corticosterone response, and its magnitude. To test this possibility, rats were adrenalectomized and the ACTH response was measured 7.5 and 15 min after the start of surgery and after injection with either 2% EtOH-saline, or 50 mug corticosterone at operation, or with 30 mug corticosterone at 5 min. Compared with ACTH levels in rats treated with vehicle, ACTH levels were decreased 7.5 min after 50 mug corticosterone at operation (P less than 0.01), but not after 30 mug corticosterone at 5 min. ACTH levels were slightly reduced 10 min after 30 mug corticosterone at 5 min compared with those of rats injected with vehicle at operation (P less than 0.05). These results are consistent with the interpretation that corticosterone secretion modifies stress-induced ACTH secretion via the fast-feedback effect. Comparison of the ACTH responses to acute adrenalectomy plus injection with EtOH-saline at 0600 and 1800 h demonstrated that, in the absence of a corticosterone response to the stress, the ACTH response is greater in the morning that in the evening (P less than 0.01). Finally, this group of experiments suggests strongly that the responsivenss of rat adrenal glands to ACTH increases markedly between 0600 and 1800 h.

The high cost of capital equipment, demands of the world markets, and continuity requirements of many technological processes have forced industry to operate three-shift, 24-hour days. Workers on fixed schedules experience no particular problems from shift work, but those who are shifted periodically can undergo physiological and emotional disturbances. These disturbances occur because most human systems function according to circadian rhythms that can be easily disoriented. The primary cause is the periodic shifting of the light-dark, wake-sleep cycles. Extensive literature exists on the cause and symptoms of disturbances in the human physiological rhythms. The information contained in this literature can be applied to protecting the health and well-being of the worker. Language: en

X-irradiation of the surgically exposed oviduct of the hen reduces the formation of albumen dry matter (which is composed essentially of protein). Over a dosage range of 0–4000 r, the irradiation effect is logarithmically related to the dose, with the albumen (dry basis) formation being reduced 40% at 4000 r. At higher doses (5000 r) irreversible changes apparently take place, since very few birds so treated return to egg production. Radioinhibition of albumen formation requires direct irradiation of the oviduct magnum tissue and, once established, appears to be more or less permanent. The functional status of the magnum tissue, relative to albumen secretion, at the time of irradiation does not appear to influence the result.

MELATONIN (5-methoxy N-acetyltryptamine) has been found to be highly localized in the pineal bodies of a number of mammalian species1,2. The melatonin synthesizing enzyme (hydroxyindole-O-methyl transferase (HIOMT)) has also been found in all mammals examined3, and is present only in the pineal gland4. Evidence has been presented demonstrating that melatonin is secreted by the mammalian pineal and acts on the gonads5. This communication describes the enzymatic synthesis of melatonin in a class other than the mammal: birds. It further demonstrates that the synthesis of melatonin is influenced by lighting, which also affects the bird gonads6.