Search

The N-terminal tripeptide of insulin-like growth factor-1, GPE is neuroprotective when given intracerebroventricularly 2 h after hypoxic-ischemic (HI) brain injury in rats. We have now examined whether GPE can cross the blood-brain barrier and exert neuroprotective actions following intravenous administration. Following a single bolus intravenous injection, GPE was rapidly metabolized and cleared from the circulation. The short half-life (

A cytochemical study of vascular and cellular development in fetal adipose tissue was conducted utilizing 10 plant lectins (fluorescein isothiocyanate (FITC)-labeled), antibodies against laminin, types II and IV collagen, and a probe for actin. Throughout fetal development (50-110 days) blood vessels were stained by galactose binding lectins and stained for actin, type IV collagen, and laminin. Adipocyte reactivity for laminin was strong throughout development, whereas adipocyte staining for type IV collagen and several lectins increased from weak to moderate between 70 and 110 days of fetal life. In general, staining intensity for lectins was greater for blood vessels than for adipocytes at every age, and staining for lectins and type IV collagen was detected much earlier on blood vessels than on adipocytes. However, the ontogeny and intensity of laminin staining were similar for developing adipocytes and vasculature. Adipocyte staining by several lectins was dependent on location within the tissue, whereas blood vessel lectin staining was not location-dependent. Neuraminidase pretreatment abolished the variation in cellular lectin staining due to location (within the tissue) but did not alter age-related changes in cellular staining. This study indicates that the differentiation of the extracellular matrix of blood vessels and adipocytes is clearly distinct in regard to glycoconjugate composition and temporal pattern of glycoconjugate and type IV collagen deposition.

Subcutaneous adipose tissue was obtained from fetuses removed from pregnant obese (Ossabaw) and lean (crossbred) sows at three stages of gestation (70, 90, and 110 days). Histochemical analysis for nucleoside phosphatase (NPase), alkaline phosphatase (APase), and NADH tetrazoleum reductase (NADH-TR) was conducted on fresh-frozen cryostat sections. Age- associated changes in NPase and NADH-TR reactions in the arteriolar system were correlated with the morphological development of the medial layer of arterioles and arteries. For instance, a strong NPase reaction in small arterioles was associated temporally with the assumption of a normal smooth muscle cell morphology and arrangement in the medial layer. In the youngest fetuses, strong NADH-TR reactions were only evident in small and presumptive arterioles and venules (associated with fat cells). Little NADH-TR reactivity was evident in larger arterioles and venules in 70-day tissue. Arteries and large arterioles were distinguished from veins and venules (strong reactions vs. weak reactions) with NADH-TR and NPase reactions in the oldest fetuses. In the younger fetuses, the NPase distinction (arterioles vs. veinules) was obvious before NADH-TR distinction. Small adipocyte-associated vessels were APase positive in the youngest fetuses, but APase reactivity was limited to short segments of vessel between arterioles and capillaries in the oldest fetuses. With the following exceptions, all the above observations were independent of fetal strain. In obese fetuses (110 day) small venules and small arterioles were equally reactive for NPase activity. Capillaries in obese fetuses (110 day) were NADH-TR reactive, whereas no activity was evident in capillaries from lean fetuses (110 day). The histology of intimal and medial vessel walls was independent of fetal strain. However, at every fetal age the adventitial layer of large arterioles and the collagenous stroma (around fat cell clusters) was thicker and better organized in obese fetuses. In the present study, differential enzyme histochemistry was utilized to distinguish the differentiation of small adipocyte-associated arterioles from larger arterioles. Furthermore, structural evidence of the arteriolar system clearly precedes metabolic and histological differentiation of tunica media cells. Finally, metabolic and structural traits of the stromal vascular cells of adipose tissue were sensitive to a fetal obese pheno-type.

The effect of upper motor neuron regulation on the development of the semitendinosus muscle was studied in the fetus. A region of the fetal spinal cord at the level of the upper cervical vertebrae was destroyed by cauterization at 45 days of gestation. Fetuses with intact spinal cords served as controls. One cauterized fetus and one control fetus were obtained from each of six crossbred sows at 110 days of gestation. From each fetus one semitendinosus muscle was removed for histochemistry and the contralateral muscle was removed, weighed and utilized for biochemical analyses. Body weights and muscle weights were not significantly different (p greater than 0.05) between the two groups. Transverse sections (cryostat) of muscle were stained for lipid and the following enzymes: acid ATPase, NADH-TR, and esterase. Lipid and enzyme cytochemistry showed that sections from cauterized and control fetuses had identical fiber type patterns. Motor endplates, as studied with esterase reactions, were not affected by spinal cord cauterization. Mean values for percentage of muscle dry weight, DNA, RNA, protein, glycogen content and minimum fiber diameters were similar for cauterized and control fetuses (p greater than 0.05). These data illustrate that in the porcine fetus the central nervous system proximal to the alpha-motoneuron exerts little control over muscle cell development.

Prednisolone and methylprednisolone were administered orally to dogs for 6 weeks in daily doses of 2.5 mg/kg and 5.0 mg/kg. Triamcinolone was similarly administered to dogs in doses of 0.5 mg/kg, 2.5 mg/kg, and 5.0 mg/kg. Two of four dogs which received triamcinolone at the rate of 5.0 mg/kg and three of four which received the same drug at the rate of 2.5 mg/kg died during the study. No deaths were produced by prednisolone or methylprednisolone. Significant loss of body weight and diuresis, as well as marked falls in hemoglobin content and packed cell volumes were produced by triamcinolone. These effects were minimal in the animals given the other steroids.