Search

Vascular smooth muscle cell (VSMC) differentiation, growth and survival, key events in the development of cardiovascular diseases, are under the control of signaling enzymes including extracellular signal regulated kinase 1/2 (ERK 1/2), Akt and epidermal growth factor receptor (EGFR) activation. EGFR trans-activation is known to mediate thrombin- or angiotensin II (AII)-stimulated ERK 1/2 activation. However, our laboratory has demonstrated, in thrombin-stimulated VSMC, that the prevention of intracellular Ca2elevation ([Ca2]i) by BAPTA-AM pretreatment unveiled EGFR-independent ERK 1/2 activation. Since calcium channel blockers (CCBs) also impair agonist-induced [Ca2]i elevation, we investigated whether EGFR-independent ERK 1/2 activation could occur in VSMCs treated by CCBs such as amlodipine, isradipine and verapamil, and examined the possible role of Akt.

The objectives of this trial were to determine the effect of dietary protein content and the effect of the source of protein supplements on dry matter intake (DMI) and milk yield in dairy cows fed ad libitum. In addition, the interaction of protein supplement with the level of milk yield was studied to test the hypothesis that the DMI response to protein supplement depends on the nutrient requirements of the cows. Two groups of six lactating cows differing in milk yield (45 kg$\cdot$d$^{-1}$ and 38 kg$\cdot$d$^{-1}$ pre-treatment) were assigned to a double 3 $\times$ 3 Latin square design over periods of 3 weeks. The 3 treatments consisted of 3 complete diets (60% maize silage and 40% concentrate) with different protein sources and levels: low-protein supplement (LP) (5% soybean meal $+$ 1.2% of urea in the diet), high-protein supplement containing soybean meal (HP-SB) (19% soybean meal) and high-protein supplement containing formaldehyde-treated soybean meal (HP-FTSB) (12% formaldehyde-treated soybean meal $+$ 1.2% of urea in the diet). HP treatments significantly increased ($P < 0.05$) DMI ($+$1.2 kg$\cdot$d$^{-1}$), milk yield ($+$1.8 kg$\cdot$d$^{-1}$), 4% FCM ($+$2.5 kg$\cdot$d$^{-1}$) and fat content ($+$1.9 g$\cdot$kg$^{-1}$) compared to the LP treatment. These improvements were not related to the source of protein used or the level of milk yield. Compared to LP treatment, the HP-SB treatment increased milk protein content ($+$1.4 g$\cdot$kg$^{-1}$) ($P < 0.05$), whereas the HP-FTSB treatment had no significant effect. Intake and milk yield were increased by higher protein content in the diets independently of the source of protein used or the level of milk yield.

The protein content of the diet modifies feed intake in lactating dairy cows, but the mechanisms are unclear. The objective of this trial was to determine whether a duodenal perfusion of protein, with or without the expected increase of milk production, plays a role in the feed intake response. Treatments were (C): control perfusion (500 g$\cdot$d$^{-1}$ of glucose $+$ 145 g$\cdot$d$^{-1}$ of urea); (P): duodenal perfusion of soy-protein isolate (500 g$\cdot$d$^{-1}$); and (Pim): the same treatment as (P) but with milk yield limited to the control by incomplete milking. Six rumen and duodenal-cannulated cows producing 35 kg$\cdot$d$^{-1}$ of milk were assigned in a double 3 $\times$ 3 Latin square design with periods of 4 weeks and inter-periods of 2 weeks. The intake, number and size of the meals, intake duration, chewing activities, digestibility (DM, OM, CP, NDF and ADF), molar proportions of volatile fatty acids and ammonia were not significantly affected by protein perfusions (P and Pim) ($P > 0.05$). Duodenal protein perfusion (P) significantly increased ($P < 0.05$) milk yield ($+$ 4.7 kg$\cdot$d$^{-1}$), protein production ($+$ 160 g$\cdot$d$^{-1}$) and protein content of milk ($+$ 1.8 g$\cdot$kg$^{-1}$) in comparison to the control perfusion (T). With incomplete milking (Pim), the milk production was the same as in the control but protein content increased ($+$ 1.9 g$\cdot$kg$^{-1}$) and fat content decreased ($-$3.2 g$\cdot$kg$^{-1}$). Incomplete milking did not reduce intake, suggesting that mechanisms controlling intake and milk production were partly dissociated.

Motility of anus and rectum has been studied in 36 normal, and 67 pathological subjects. Normal mechanical characteristics in resting state and after stimulations are shown to be necessary for normal continence. Normal values are determined in normal subjects. In spina bifida, higher rectal activity is described, and normal anal resting and relaxing pressures are shown in continent subjects. In Hirschsprung's disease, defect of ano-rectal inhibitory reflex is confirmed, and normal anal pressures are found. In operated anorectal malformations, incontinence always corresponds with defect of recto-anal inhibitory reflex, lower length of anal resistance, or no functional striated sphincteric muscles.