@article{tyler_vigna_mcvey_croom_1994, title={DEVELOPMENTAL APPEARANCE OF PEPTIDE-BINDING SITES IN THE SMALL-INTESTINE OF THE NEONATAL PIGLET}, volume={74}, ISSN={["0008-3984"]}, DOI={10.4141/cjas94-034}, abstractNote={ The ontogeny of the expression of specific binding sites for bombesin (BBS), vasoactive intestinal polypeptide (VIP), and gastrin in the neonatal pig was examined. Piglets were sacrificed at birth, 1 d, 1 wk, 3 wk and 4 wk, and samples of duodenal, jejunal and ileal tissue were harvested for autoradiographic analysis of saturable radioligand binding. Monoiodinated, biologically active 125I-Tyr4-BBS, VIP or gastrin (100 pM) was applied to slide-mounted sections of piglet intestinal tissue and localized using autoradiographic analysis of radioligand binding. Saturable binding sites for 125I-BBS first appeared in duodenal tissue of 7-d-old piglets, with evidence for continued presence in this tissue through 21 d. BBS binding sites were localized in duodenal mucosa, with no detectable binding in any other tissue layers. No evidence for saturable binding of 125I-Tyr4-BBS was found in intestinal sections from either newborn, 1-d-old or 4-wk-old piglets. Saturable binding sites for 125I-VIP were present in duodenal, jejunal and ileal tissues of piglets at all ages studied and were present in both the mucosa and the muscularis externa. No saturable binding sites for 125I-gastrin were observed in intestinal sections from piglets at any of the ages studied. These results suggest potential sites of direct action of VIP in newborn, suckling and newly weaned piglets. Bombesin, however, may have direct actions only on the duodenal mucosa at 7–21 d of age. Key words: Bombesin, vasoactive intestinal polypeptide, gastrin, piglet, small intestine, newborn }, number={2}, journal={CANADIAN JOURNAL OF ANIMAL SCIENCE}, author={TYLER, HD and VIGNA, SR and MCVEY, DC and CROOM, WJ}, year={1994}, month={Jun}, pages={243–249} }
 @article{tyler_ramsey_1993, title={EFFECT OF FRUCTOSE-INDUCED HYPOGLYCEMIA ON CESSATION OF MACROMOLECULAR TRANSPORT IN THE NEONATAL CALF}, volume={76}, ISSN={["0022-0302"]}, DOI={10.3168/jds.S0022-0302(93)77641-9}, abstractNote={Fructose was used as a hypoglycemic agent to determine whether availability of glucose during early life mediates the cessation of intestinal transport of Ig (closure). Either glucose or fructose (100 g in 2 L of electrolyte solution) was fed to calves deprived of colostrum at 3, 6, 9, 12, 15, 18, and 21 h postpartum. Colostrum (1 kg) was fed to all calves at 24, 36, and 48 h postpartum. Venous blood was sampled, and plasma was harvested, for the measurement of glucose, fructose, insulin, and IgG. During the first 24 h, means for plasma glucose from calves treated with glucose and fructose, respectively, were 282 and 24 mg/dl. The latter value reflects the degree of hypoglycemia induced by feeding fructose. During the same period, corresponding concentrations of plasma fructose were 4 and 230 mg/dl. Plasma insulin concentrations for precolostral calves were 101 and 11 microU/ml for calves treated with glucose and fructose, respectively. Peak IgG concentrations were extremely low for both groups of calves, indicating that intestinal transport of Ig had virtually ceased by the end of the 24-h treatment period. Thus, fructose-induced hypoglycemia had no effect on the time of intestinal closure in the newborn calf.}, number={10}, journal={JOURNAL OF DAIRY SCIENCE}, author={TYLER, H and RAMSEY, H}, year={1993}, month={Oct}, pages={3021–3025} }
 @article{tyler_ramsey_1993, title={EFFECT OF INSULIN-INDUCED HYPOGLYCEMIA ON CESSATION OF MACROMOLECULAR TRANSPORT IN THE NEONATAL CALF}, volume={76}, ISSN={["0022-0302"]}, DOI={10.3168/jds.s0022-0302(93)77610-9}, abstractNote={The effect of hypoglycemia on the absorption of colostral Ig was studied in 12 neonatal calves. Hypoglycemic calves received 1 cc (100 units) of insulin at birth; control calves received 1 cc of saline. Two dietary regimens were imposed; colostrum was fed at birth or at 24 h. Glucose, insulin, and IgG were measured in venous blood. Insulin induced decreases in circulating glucose in insulin-treated calves from 12 to 42 h postnatally; insulin concentrations were significantly higher from 12 through 24 h. Concentrations of glucose also were decreased in calves deprived of initial colostrum compared with those fed at birth over the same period, although insulin concentrations were not different. Time of closure was delayed in insulin-treated calves relative to saline-treated calves (40 and 29 h, respectively) and in calves deprived of initial colostrum relative to those fed at birth (45 and 23 h, respectively). Glucose availability may influence timing of closure in the calf, although the decreased rate of absorption of IgG in hypoglycemic calves prevents them from realizing any benefit in peak IgG concentrations higher than those of their normoglycemic counterparts.}, number={9}, journal={JOURNAL OF DAIRY SCIENCE}, author={TYLER, H and RAMSEY, H}, year={1993}, month={Sep}, pages={2736–2741} }
 @article{tyler_ramsey_1991, title={HYPOXIA IN NEONATAL CALVES - EFFECT ON INTESTINAL TRANSPORT OF IMMUNOGLOBULINS}, volume={74}, ISSN={["0022-0302"]}, DOI={10.3168/jds.S0022-0302(91)78361-6}, abstractNote={The effect of reduced oxygen tension in arterial blood (hypoxic hypoxia) for 24 h postpartum on the absorption of colostral Ig was studied in 12 neonatal calves. During this period, inspired air for hypoxic calves contained 10.5% O2, whereas that for normoxic calves contained 21% O2. After 24 h, inspired air for all calves contained 21% O2. Three dietary regimens also were imposed during the initial 24-h period: colostrum at 0 and 12 h, whole milk at 0 and 12 h, or fasting. Colostrum was fed to all calves at 24, 36, and 48 h. During the initial 24-h period, means for arterial partial pressure of oxygen were 26 and 73 mm Hg for hypoxic and normoxic calves, respectively. In those fed colostrum at 0 and 12 h, hypoxia extended the period of Ig absorption from 20 to 40.5 h. In calves fed whole milk or those that were fasted, no such effect was noted. These observations suggest that the effect of hypoxia on the cessation of Ig absorption by the small intestine is mediated through a secondary and as yet undetermined mechanism.}, number={6}, journal={JOURNAL OF DAIRY SCIENCE}, author={TYLER, H and RAMSEY, H}, year={1991}, month={Jun}, pages={1953–1956} }
 @article{tyler_ramsey_1991, title={HYPOXIA IN NEONATAL CALVES - EFFECT ON SELECTED METABOLIC PARAMETERS}, volume={74}, ISSN={["0022-0302"]}, DOI={10.3168/jds.S0022-0302(91)78362-8}, abstractNote={The effect of reduced oxygen tension in arterial blood (hypoxic hypoxia) for 24 h postpartum on selected metabolic parameters was studied in 12 neonatal calves. During this period, inspired air for hypoxic calves contained 10.5% O2, whereas that for normoxic calves contained 21% O2. After 24 h, inspired air for all calves contained 21% O2. Three dietary treatments also were imposed during the initial 24-h period: colostrum at 0 and 12 h, whole milk at 0 and 12 h, or fasting. All calves were fed colostrum at 24, 36, and 48 h and whole milk at 60 and 72 h. Parameters included plasma glucose, lactate, fructose, and IgG; arterial blood gases; and pH. Arterial partial pressure of oxygen was maintained near 25 mm Hg throughout the period of hypoxia. Arterial partial pressure of carbon dioxide was unchanged during the period of hypoxia (approximately 45 mm Hg) but was lower (39 mm Hg) in posthypoxic calves. Glucose tended to be lower in hypoxic calves; however, this difference was not statistically significant. Hypoxic calves had significantly higher plasma lactate concentrations contributing to a progressive primary metabolic acidosis.}, number={6}, journal={JOURNAL OF DAIRY SCIENCE}, author={TYLER, H and RAMSEY, H}, year={1991}, month={Jun}, pages={1957–1962} }
 @article{tyler_ramsey_1990, title={Effect of fructose-induced hypoglycemia on cessation of intestinal transport of immunoglobulins in newborn calves}, volume={73}, journal={Journal of Dairy Science}, author={Tyler, H. D. and Ramsey, H. A.}, year={1990}, pages={219} }
 @article{tyler_ramsey_1989, title={Effect of hypoxia on cessation of intestinal transport of immunoglobulins in newborn calves}, volume={72}, journal={Journal of Dairy Science}, author={Tyler, H. D. and Ramsey, H. A.}, year={1989}, pages={316} }