A survey of the non-esterified fatty acids and binding proteins in the plasmas of selected animals

• 1.1. The levels of non-esterified fatty acids (NEFA) in the plasma of a variety of animals have been estimated.
• 2.2. Only one of seven elasmobranchs contained detectable levels of NEFA.
• 3.3. The two crustaceans examined contained very low levels.
• 4.4. All the other animals contained circulating levels of a variety of NEFA ranging from 14 to 24 carbon atoms.
• 5.5. The elasmobranchs are unique in that they also do not possess proteins in the serum which bind fatty acids.

     

Comparative hematology: Studies on cats including one with factor XII (hageman) deficiency

• 1.1. Cat plasma prothrombin and partial thromboplastin times are faster than human. Thromboplastin generation tests are very similar.
• 2.2. Factors VIII and V assay 24 and 13 times the human standard. Cat factors VII, X. IX, XI and XII assayed at 2.5 to 4 times human. Factors I, II and XIII fell within the human range and Fletcher was extremely low.
• 3.3. One cat lacked factor XII and showed a prolonged APTT and clotting time.
• 4.4. Cat profibrinolysin was activated by streptokinase but not by urokinase.
• 5.5. Cat platelets aggregated with the usual human aggregation agents with the exception of thrombin and ristocetin.
• 6.6. Cat erythrocytes were smaller and more numerous than human.
• 7.7. Leukocyte counts were quite variable.
• 8.8. Serum protein electrophoretic patterns differed from human in the greater migration of albumin and the presence of numerous unidentified bands.
• 9.9. Biochemical tests showed high sodium and chloride values.

     

Analysis of clotting defects in diseased lobsters—II. Immunochemical study of blood proteins

• 1.l. In gaffkemic lobsters kept at 15°C, the plasma coagulogen amount rapidly decreases and the gelation of hemolymph is prevented.
• 2.2. In animals kept at 10°C, the available plasma coagulogen amount is always normal even when coagulation appears impaired or prevented.
• 3.3. Extended clotting times as well as damaged coagulation cannot be correlated with coagulogen concentration.
• 4.4. The site of synthesis of this factor is discussed.

     

Plasma lipoprotein profiles and arylesterase activities in two inbred strains of rabbits with high or low response of plasma cholesterol to dietary cholesterol

• 1.1. Cholesterol feeding for 4 weeks of female and male rabbits of two inbred strains increased plasma cholesterol concentrations by about 11 and 48 mmole/I in the hypo- and hyperresponsive strain, respectively.
• 2.2. On the low-cholesterol pre-experimental diet, the hyporesponsive animals had significantly higher plasma HDL (high density protein) cholesterol levels than hyperresponders.
• 3.3. In both strains, cholesterol feeding caused elevations of cholesterol in all lipoprotein classes, the difference between the hypo- and hyperresponsive strains in essence only being observed in the VLDL (very low density lipoprotein) fraction.
• 4.4. Basal plasma total arylesterase activity was significantly higher in the hypo- than in the hyperresponsive rabbits.
• 5.5. Dietary cholesterol caused an increase in plasma esterase activity in both strains.
• 6.6. We suggest that in rabbits a low plasma arylesterase activity and a low concentration of HDL cholesterol are associated with an increased sensitivity to dietary cholesterol.

     

The effects of osmotic stressors on the stenohaline carp (Cyprinus carpio)

• 1.1. Carp were acclimatized to different concentration of urea and mannitol.
• 2.2. The fish survived in 300 mOsm urea and 262 mOsm mannitol for a longer period. Higher concentrations were only tolerated for a short time.
• 3.3. Urea penetrated into the animals. The internal concentration of urea in plasma was nearly equal to the outside concentration after 7 days. Therefore a very high internal osmolality was adjusted (sum of normal and urea osmolality).
• 4.4. Urea treatment only resulted in changes of Ca level, while the concentration of other electrolytes was not clearly varied.
• 5.5. Extracellular space of muscle was reduced while the intracellular space remained unchanged after urea treatment.
• 6.6. Mannitol treatment resulted in changes of electrolyte concentrations due to dehydration.
• 7.7. After 1 day of treatment the concentration of Na in plasma decreased which might indicate the limitation of tolerance.
• 8.8. Immediate shrinkage of ICS and, later, reduction of ECS were clear reactions to mannitol influence.

     

Effects of photoperiod on plasma corticoid levels in the goldfish,Carassius auratus—role of the pineal

• 1.1. The effects of photoperiod and pinealectomy on plasma corticoid levels in the goldfish (Carassius auratus) were examined.
• 2.2. Plasma corticoid levels differed in goldfish maintained under different photoperiod regimes, but this response varied seasonally.
• 3.3. Pinealectomy altered the effects of photoperiod on plasma corticoid levels but this effect varied with season.
• 4.4. Plasma corticoid levels were correlated with ovarian activity. The effects of photoperiod on plasma corticoid levels appear to be related to the influence of light on reproduction.
• 5.5. The alteration of plasma corticoid levels in pinealectomized fish may be due to the role this organ plays in mediating photoperiod effects on gonadal activity.

     

Effects of streptozotocin-diabetes and l-thyroxine treatment on TSH and GH,and circulating glucose and glycerol in thyroidectomized rats

• 1.1.The response to exogenous thyroxine in thyroidectomized rats made diabetic by treatment with streptozotocin was greatly impaired, as shown by their growth retardation and the lack of increase in plasma GH and pituitary GH and TSH concentrations.
• 2.2.Insulin administration partially compensated for these endocrine alterations in diabetic thyroidectomized rats. When these animals received enough exogenous thyroxine to normalize their plasma PBI and TSH levels, insulin administration did not decrease their augmented glucose and glycerol concentrations.
• 3.3.These findings show the permissive action between thyroid hormones and insulin although some effects of the former counteract those of insulin.

     

Induction of prothrombin biosynthesis and inhibition of gamma carboxylase activity in experimental models of liver regeneration and fibrosis

• 1.1. When acute liver damage is induced in rats treated with CCl₄, both prothrombin biosynthesis and gamma carboxylase activity decreases, originating a prolongation of prothrombin time in plasma.
• 2.2. Then, during the regenerative process, prothrombin biosynthesis increases higher than normal, but gamma carboxylase activity remain decreased. In this case, prolongation of prothrombin time occurs in spite of high levels of descarboxylated prothrombin in plasma.
• 3.3. An increase of descarboxylated prothrombin in plasma is also detected in the CCl₄-liver fibrosis model.

     

Facultative aestivation in a tropical freshwater turtle Chelodina rugosa

• 1.1. Chelodina rugosa dug from aestivation sites at the end of the dry season were immediately alert and well coordinated.
• 2.2. Compared with non-aestivating animals, aestivating turtles had 20% higher plasma osmotic pressure and 7% higher sodium. Coupled with a small, but significant weight gain upon return to the water, this suggested the occurrence of minor dehydration in aestivating animals.
• 3.3. Plasma lactate levels of aestivating animals were low, averaging 1.99 mmol/l, consistent with aerobic rather than anaerobic metabolism having sustained their long period under ground.
• 4.4. No evidence was seen of dramatic physiological specialization. Aestivation in this species is interpreted as a primarily behavioural adaptation, made possible by typically reptilian abilities to tolerate a wide range in plasma electrolytes and to survive long periods without feeding.

     

Immobilization stress-induced antioxidant defense changes in rat plasma: Effect of treatment with reduced glutathione

• 1.1. We examined immobilization stress-induced antioxidant defense changes in rat plasma and observed the antioxidant effect of reduced glutathione (GSH) administration on these changes.
• 2.2. Immobilization stress induced severe bleeding in the stomach and a significant increase in plasma levels of thiobarbituric acid receives substances (TBARS).
• 3.3. Immobilization stress induced a significant decrease in plasma iron-binding, ironoxidizing protections and radical scavenging activity.
• 4.4. Plasma levels of ascorbic acid, ascorbyl radical and superoxide dismutase activity remained unchanged following immobilization stress.
• 5.5. Treatment with GSH showed a significant protective effect on stomach bleeding, on the increase in plasma TEARS, and on the decrease of iron-binding, iron-oxidizing protection and radical scavenging activity in plasma.
• 6.6. These results suggest that immobilization stress induces generation of reactive oxygen species and decreases the endogenous antioxidant defenses, which can be attenuated by extracellular administration of antioxidant GSH.

     

Cholesterol metabolism in new world primates: Comparative studies in two tamarin species (Saguinus oedipus and Saguinus fuscicollis) and the squirrel monkey (Saimiri sciureus)

• 1.1. Cholesterol metabolism has been characterized in three species of New World primates, the cotton-top tamarin, the saddle-back tamarin, and the squirrel monkey.
• 2.2. When fed a diet containing cholesterol, the three species exhibited differing responses of plasma cholesterol levels.
• 3.3. Dietary cholesterol absorption was determined and plasma cholesterol die-away kinetics were analyzed in terms of a two-pool model.
• 4.4. The results of the analyses of cholesterol turnover are consistent with the observed species-specific differences in plasma cholesterol values and cholesterol absorption.
• 5.5. Cholesterol metabolism differs between the two tamarin species, as well as between the tamarins and the squirrel monkey.
• 6.6. Implications of species-specific differences between tamarin species are discussed in terms of the use of tamarin species as animal models for comparative studies of cholesterol metabolism and the etiology of cancer and cardiovascular disease.

     

Rank-associated desynchronization of metabolic and activity rhythms of Peromyscus maniculatus in response to social pressure

• 1.1. Saturation level population density conditions drastically affected the level and timing of subordinate males' metabolic rate and locomotor activity and feeding rhythms.
• 2.2. The increased daily metabolic rates of subordinate animals was expressed in the face of depressed locomotor and feeding activity levels.
• 3.3. A phase shift in the metabolic peak of dominant animals occurred at high density, but close synchrony between activity and metabolic rate persisted with no increase in metabolic cost.
• 4.4. Subordinate animals showed desynchronization of activity rhythm at high density; this effect imposed a higher bioenergetic cost upon the subordinate than upon the dominant mice.

     

Sex-specific androgen binding in spotted hyaena (Crocuta crocuta) plasma

• 1.1. A charcoal adsorption assay demonstrated a large variance in androgen binding ability in female spotted hyaenas.
• 2.2. A positive correlation between plasma androgen binding ability and ovarian steroid concentrations was demonstrated in adult females.
• 3.3. The strong plasma binding affinity for testosterone and dihydrotestosterone (DHT) (nM) together with the lack of cortisol and weaker oestradiol-17β binding suggests that a specific androgen binding substance, possibly a protein, is present in adult females of this species.
• 4.4. The lack of high affinity binding in male spotted hyaenas is unusual and deserves further investigation.
• 5.5. Some androgen binding in all, including males and immature animals suggests that albumin may bind some plasma androgens in this species.

     

Oxygen consumption of the sandy-beach whelk Bullia digitalis meuschen at different levels of activity

• 1.1. O₂ consumption of suspended Bullia digitalis is not related to water current speed or degree of turbulence, where these are kept constant.
• 2.2. The highest levels of O₂ uptake at 15°C are obtained by producing fluctuating surges of turbulence, the animals responding to changes in the movement of water.
• 3.3. In buried animals O₂ consumption decreases with time in the absence of water movements.
• 4.4. Burrowing and surface crawling require less energy than transport in the surf.

     

Effects of starvation and a carbohydrate-rich diet on glycogen metabolism in a gastropod mollusc,Megalobulimus oblongus

• 1.1. Administration of a carbohydrate-rich diet increased haemolymph glucose levels and glycogen concentration in hepatopancreas, mantle and muscle.
• 2.2. Glycogen concentration in tissues decreases after 2 weeks of starvation and haemolymph glucose levels did not change significantly.
• 3.3. However, starvation did not induce a decrease in the intrinsic synthetic capacity in tissues.
• 4.4. Glycogen synthesis in tissues from animals fed with lettuce or a carbohydrate-rich diet, increases with increasing glucose concentration in the media.
• 5.5. However, in mantle slices from snails adapted on a carbohydrate-rich diet, the glycogen synthetic capacity was lower than in slices from snails fed with lettuce.

     

Effects of lysine administration on plasma arginine and on some nitrogenous catabolites in rainbow trout

• 1.1. Rainbow trout were fed either graded levels of lysine (0.8, 1.8 and 3%) at a constant level of arginine (1.4%) or excess arginine (2.4%) at a fixed level of lysine (1.8%).
• 2.2. Increasing the dietary lysine level affected plasma urea, plasma arginine and ammonia excretion.
• 3.3. Trout fed graded levels of lysine received an arginine challenge (U¹⁴C-l-arginine) and it was found that excess dietary lysine led to a decrease in arginine degradation.
• 4.4. Injection of l-lysine induced a decrease in urea excretion, while injection of l-arginine increased both urea and ammonia excretion in control well-fed trout.
• 5.5. These results are discussed in the light of current knowledge on the antagonism between lysine and arginine.

     

Seasonal effects of prolactin on aspects of carbohydrate and lipid metabolism in the goldfish,Carassius auratus

• 1.1. Diurnal and seasonal variations of certain aspects of carbohydrate and lipid metabolism to ovine prolactin (PRL) treatment in the goldfish, Carassius auratus, were examined.
• 2.2. PRL treatment late in the light phase of a long photoperiod during spring depletes liver glycogen stores. During fall liver glycogen levels are not affected by PRL treatment in fishes acclimated to long or short photoperiods. PRL is hypoglycaemic in fall and spring.
• 3.3. PRL administered late in the light phase of a long photoperiod during spring increases plasma and liver total lipids and plasma cholesterol, while decreasing plasma triglycerides. In fall PRL may increase or decrease plasma organic-bound P levels dependent upon injection time.

     

The effect of pyridoxine deficiency on aminotransferase activity in liver and white muscle of rainbow trout (Salmo gairdneri Richardson)

• 1.1. Aspartate aminotransferase activity in the white muscle of rainbow trout dropped significantly after the animals had received a pyridoxine-deficient diet for 7 days.
• 2.2. Alanine aminotransferase activity in the white muscle of rainbow trout dropped significantly after the animals had been fed on a pyridoxine-deficient diet for 21 days.
• 3.3. Alanine and aspartate aminotransferase activity in the liver of rainbow trout did not drop significantly until the animals had received a pyridoxine-deficient diet for 28 days.
• 4.4. After rainbow trout have received a pyridoxine-deficient diet for 35 days, feeding with complete diet for 7 days is sufficient to restore the aminotransferase activities to the levels observed in control animals.

     

Factors influencing lipid levels and lecithin:cholesterol acyltransfer in plasma of the lizard,Tropidurus torquatos

• 1.1. Lipid concentrations and lecithin:cholesterol acyltransferase (LCAT) activity in the plasma Tropidurus torquatos were remarkably variable.
• 2.2. Both lipid levels and LCAT activity were highest for lizards collected during the early rainy season (March–April) than during other seasons, and were higher for females than for males.
• 3.3. Plasma lipid levels and LCAT activity were significantly and inversely correlated with body weight (age) of male lizards, this being associated with an apparent change to an herbivorous diet in older males.
• 4.4. During prolonged fasting, plasma lipid levels and lecithin:cholesterol acyltransfer (LCAT) and hepatic phospholipids were markedly reduced.
• 5.5. LCAT activity in plasma of fasted and non-fated lizards was significantly correlated with the molar proportion of PC to UC, suggesting that the apparent low LCAT in plasma of fasted lizards is partly due to depletion of PC in the lipoprotein substrates.

     

Adaptation of rainbow trout (Salmo gairdnerii) to sea water: Changes in calcitonin levels

• 1.1. The calcitonin content of the ultimobranchial body (UBB) and plasma levels of calcitonin, calcium and phosphate were measured in rainbow trout (Salmo gairdnerii) following their transfer from fresh to sea water.
• 2.2. The plasma calcium level remained unchanged throughout the experiment while the UBB calcitonin content, plasma calcitonin and plasma phosphate rose significantly during the hours immediately following transfer.
• 3.3. The levels of all three subsequently fall so that, 8–15 days later, a new equilibrium was established with lower than control (fresh water) levels of UBB calcitonin, plasma calcitonin and plasma phosphate.
• 4.4. It would appear, from these data, that calcitonin plays some part in the endocrine regulation of sea water transfer.