This paper continues the development begun in Part I (15), to show in what way it is meaningful to reduce biological phenomena to physical theory at any level of organization. The appropriate level-independent physics is comprised of thermostatics, thermodynamics of irreversible processes, statistical mechanics, and nonlinear mechanics. Generalized, these approaches lead to a spectroscopic description of the constellation of periodic processes that constitute the living states. The spectroscopic description is here applied also to the inputs received by living systems, from lethal, high-energy, nuclear particles and radiation to low-energy communicational signals that make up languages understandable at the various levels in an hierarchical system. The concept of language is then itself generalized, showing how the empirical relation discovered by Zipf can be derived from a thermodynamic basis. It is demonstrated that certain linguistic and statistical-mechanical distribution functions can be related. Applications of the field thermodynamic approach to two problems in transport phenomena are given in APPENDIX I; applications of field thermodynamics to language and communication are given in APPENDIX II.

The response of blood glucose (BG), free fatty acids (FFA), and insulin (IRI) to both intravenous (IVGTT) and oral (OGTT) glucose tolerance tests was evaluated in unrestrained, permanently catheterized squirrel monkeys. The mean glucose assimilation rate (K value) for 25 IVGTT was 7.75 +/- 2.84. FFA maximally decayed 54 percent from a mean basal of 1,008 +/- 221 mueq/l associated with a onefold increment inIRI from basal (7.5 +/- 3.5 muU/ml) at 2-5 min. No significant changes were found during intravenous saline loading alone. OGTT (4g/kg) produced peak BG levels at 15-30 min with an immediate FFA decrease of 63 percent and a onefold IRI increment. Carcass composition analyses from 17 animals showed a total extractable lipid content of 6.2 percent. The K value, significantly higher than previously reported, appears to fit well with that expected for the species. The rapid decrease in FFA and BG concentrations demonstrate an apparent high efficiency of a low IRI increment. The association of the low IRI after loading with a low triglyceride depot is discussed.

This paper provides mathematical solutions for calculating calcium fluxes and compartments in isolated kidney cells from calcium-45 desaturation curves. In contrast to other available methods, these solutions allow the calculation of kinetic parameters even if isotopic equilibrium has not been reached at the beginning of the desaturation period. To test the validity of the method, calcium-45 desaturation experiments were performed in isolated kidney cells after labeling periods of 30, 60, 90, or 120 min. Even though the calcium-45 desaturation curves differ with different labeling times, the respective values of the calculated parameters are practically identical. The optical labeling period was found to lie between 60 and 120 min. Since this new method does not require initial isotopic steady state, it allows a formal kinetic analysis of tracer desaturation curves even after short periods of labeling.

This paper describes a method to measure calcium fluxes and calcium exchangeable pools in tissue slices by continuous perifusion in flow-through chambers. 45Ca desaturation from rat kidney slices can be analyzed as in an open three-compartment catenary system. A set of equations is given to calculate all the relevant kinetic parameters from the triple exponential equations which best fit the desaturation curves. The results show that the kinetic parameters obtained in kidney slices by this new method are in the same order of magnitude as those previously observed in cultured monkey kidney cells.

Characteristics of the fast, rate-sensitive, negative-feedback regulation of adrenocorticotropin secretion during stress was quantitatively analyzed using rats anesthetized with pentobarbital sodium. Various levels of plasma corticosterone were achieved during morning hours by infusing corticosterone solutions of different concentrations. Blood was sampled serially from the carotid artery. An increase in plasma corticosterone concentration 15 min after intravenous, pulsed injection of histamine (230 microgram) during saline intravenous infusion was defined as the “control response”. When plasma corticosterone was rising during corticosterone infusion, the response to histamine stimulus was distinctly inhibited (fast, rate-sensitive feedback inhibition), whereas such an inhibition was not observed when plasma corticosterone levels were not rising, regardless of the absolute level. The critical rate of rise of plasma corticosterone, at or above which the fast rate-sensitive feedback was manifested, was 4-6 microgram/100 ml per min. When three graded doses of histamine were injected while plasma corticosterone levels were increasing at a rate of 6 microgram/100 ml per min, the absolute value of the inhibition observed was indepxendent of the administered dose of the stressor. A hypothetical model for the mechanism of this feedback inhibition, based on the assumption that the hormone effect was proportional to the rate of formation of hormone-receptor complex, satisfied the quantitative characteristics of the inhibition experimentally observed in this study.

Blood-brain and blood-CSF barriers to inulin were compared in 11 vertebrate species. Twenty hours after systemic administration, [14C]inulin penetrated into the central nervous system to an equivalent extent in mudpuppy, salamander (adult and larval), red sculpin, big skate, little skate, southern stingray, and Atlantic stingray with values for RB (dpm/g brain divided by dpm/ml plasma) in the range 0.01- 0.04 and for RCSF (dpm/ml CSF divided by dpm/ml plasma) from 0.02 to 0.04. These values are similar to those reported for mammals. For dogfish, nurse shark, and lemon shark, RB ranged from 0.04 to 0.09 and RCSF from 0.08 to 0.29 and for hagfish RB=0.12, indicating that barrier systems to inulin are poorly developed in sharks and possibly absent in hagfish. Analyses of radiolabeled urea and sucrose penetration into brain and CSF revealed further differences in shark barrier function. Brain barriers to insulin in dogfish and little skate developed with age; in nurse shark there was no detectable change in the inulin ratios over the weight range, 0.2-110 kg.

The effects of intravenous infusion of Asp1. Ile5-angiotensin II on blood pressure, plasma vasopressin, ACTH and 11-hydroxycorticosteroid levels and on plasma renin activity were studied in five trained, conscious dogs. The dogs were prepared with bilateral carotid loops. Infusion of angiotensin II at rates of 5, 10, and 20 ng/kg.min raised its plasma concentration from 23 +/- 7 to 48 +/- 8, 125 +/- 8, and 187 +/- 21 pg/ml, respectively. The lowest rate of infusion was mildly pressor, the two higher rates more so. All rates of infusion promptly increased vasopressin levels and depressed renin levels. The two higher rates also stimulated ACTH, although with a latency of 30-45 min. Since the rates of infusion of angiotensin II employed produced plasma levels within the physiological range, it is suggested that peripherally generated angiotensin II may play an important role in the regulation of vasopressin, and ACTH secretion.

Data dealing with placental respiratory gas exchange are scant for species with an epitheliochorial placenta. None have been obtained from awake, unstressed animals. For this reason 18 pregnant swine were prepared with chronically implanted polyvinyl catheters. Respiratory gases in arterial and uterine venous blood were observed between the 30th day of gestation and term (110 days). There was a statistically significant relationship between uterine venous oxygen partial pressure (Po₂ and the day of gestation. The value for Po₂, fell from a mean of 70 to 57 Torr. The latter appears to be the highest mean value yet observed in uterine vein of any species at term. pregnancy; chronic preparation Submitted on March 7, 1977