Resting systolic, diastolic, and mean blood pressures (MBP), as well as heart rates, of unanesthetized, unrestrained, cold-acclimated (CA, 4 wk, 6 degrees C) rats were measured by direct arterial cannula and compared with those of controls maintained at 25 degrees C. Exposure to cold increased all these measurements significantly. Mean heart weight of CA rats was also increased significantly above that of controls. The responsiveness of MBP and heart rate to administration of the beta-adrenergic agonist, isoproterenol (3, 5, and 8 micrograms/kg ip), to unanesthetized, unrestrained, CA rats during exposure to air at 6 degrees C was similar to, and possibly less than, that of warm-acclimated (WA) rats measured at 25 degrees C. Acute administration of the alpha-adrenergic agonist, phenylephrine (100 micrograms/kg ip), to CA rats while in air at 6 degrees C induced less of a change in MBP from pretreatment level than was observed in WA rats. However, no differences were observed between groups when changes in heart rate from pretreatment level were compared. A similar statement may be made for a higher dose of phenylephrine (150 micrograms/kg ip), although MBP were elevated to higher levels in both groups with the higher dose. Abrupt exposure of WA rats to cold (6 degrees C) resulted in a sharp increase in heart rate and a more gradual increase in MBP over a period of 1 h. Removal of CA rats from 6 to 25 degrees C resulted in a gradual decrease in heart rate with no significant change in MBP during the ensuing hour.(ABSTRACT TRUNCATED AT 250 WORDS)

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Stimulation of the oral cavity immediately elicits salivation, gastric acid secretion and pancreatic exocrine and endocrine secretions that serve to prepare the alimentary canal for digestion, transport and utilization of ingested nutrients. Oropharyngeal-stimulated responses are reliably initiated by the taste and smell of food. These gastrointestinal reflexes, often referred to as anticipatory or cephalic phase responses, are mediated by the autonomic nervous system and are believed to be independent of the postabsorptive effects of ingested nutrients. A common pathway used by cephalic phase responses to trigger gastrointestinal secretions is the vagus. Several studies have also demonstrated that cephalic stimulation activates both the sympathetic and parasympathetic nervous systems and thus, many cephalic-metabolic reflexes may arise indirectly from more general physiological changes that accompany oropharyngeal stimulation. The present studies suggest that oral stimulation results in alterations in intestinal function. Specifically, oropharyngeal stimulation of conscious, unrestrained rats with sucrose increases the uptake of radioactive glucose from the small intestine into the hepatic portal blood.

The binding of 8-anilino-1-naphthalenesulfonate to bovine serum albumin was reinvestigated. A fluorescence method was used to obtain the binding data which were treated appropriately to obtain the number of binding sites and the equilibrium constants. The results confirm that the number of binding sites for 8-anilino-1-napthalenesulfonate on bovine serum albumin is 3. The individual binding constants were calculated by using the Bjerrum technique. The average values of the three constants are K , = 2.9 X lo6, K2 = 6.1 X lo5, and K3 = 5.6 X lo5. 8-Anilino-1-naphthalenesulfonate (ANS) has been extensively used as a fluorescent probe for such studies as the quantitative analysis of serum proteins ( I ) , the study of the polarity of binding sites on proteins ( 2 ) , and the determination of the protein-binding parameters of other drugs by competitive binding (3, 4 ) . Rees and coworkers ( I ) reported the use of ANS for the assay of serum proteins.However, it was Daniel and Weber ( 5 ) who studied the interaction between ANS and bovine serum albumin (BSA) in detail, They reported that the interaction was reversible with an average binding constant of about lo6, and that five molecules of ANS were bound per molecule of BSA. Recently Ma, Jun, and Luzzi (6) have published new data on ANS-BSA binding. Their value for the average binding constant agrees well with that reported by Weber. However, they found that the maximum number of binding sites, N , on BSA, for ANS was three rather than five. Because of these conflicting results, it was decided to reinvestigate the ANS-BSA binding interaction. EXPERIMENTALSodium 8-anilino-1-naphthalenesulfonate was purchased from Eastman Organic Chemicals, Rochester, N.Y. The sodium salt was purified by passing an aqueous solution of the salt through an Amberlite IR-120 (Mallinckrodt) column, and then further purified by crystallization from water. Crystalline bovine serum albumin of A grade (Pentex brand product of Miles Laboratory) was supplied by Calbiochem, San Diego, Calif. Commercially prepared BSA usually contains fatty acids as impurities and can be purified by acid charcoal treatment ( 7 ) . However, Chen ( 7 ) has shown that Pentex brand BSA contains only about 1 mole of fatty acid per mole of BSA. Moreover, Santos and Spector (8) have reported that up to 2 moles of long chain fatty acid per mole of BSA do not affect the ANS-BSA binding. Consequently, the pretreatment of BSA with acid charcoal was deemed unnecessary. Because of the hygroscopic nature of BSA, it has been common practice not to accurately weigh samples routinely for dissolution in water, but rather to photometrically determine the absorbance at 280 nm of aqueous solutions containing roughly weighed BSA samples. The concentration in g/l. is obtained from Beer's law, assuming a value of E ;Trn of 6.60 ( 4 ) or in moles/l. by assuming as well the average molecular weight of 69,000 (9, IO) so that c = 4.55 X IO4 at 280 nm. In our experience, during the course of an average accurate weighing (in the extremely humid ...