Eccrine sweat gland activity in heat acclimation

The response of eccrine sweat glands of the forearms of four females was investigated during acclimation to heat. The sweat rate increased progressively during ten exposures. There was no significant change in the number of active sweat glands. The increased sweat rate could, therefore, be attributed to enhanced secretory activity of individual glands.

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Zusammenfassung Die Schweissdrüsenreaktion des Vorderarms von 4 Frauen wurde während der Akklimation an Hitze untersucht. Die Schweisssekretion stieg progressiv während 10 Sitzungen an. Eine signifikante Änderung in der Zahl der aktiven Schweissdrüsen wurde nicht beobachtet. Die gesteigerte Schweisssekretion beruht danach auf einer vermehrten Schweissbildung der einzelnen Drüsen.

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Resume On a étudié les réactions des glandes sudoripares de quatre femmes pendant la période d'acclimation à la chaleur. La sécrétion de sueur a augmenté progressivement durant 10 heures. On n'a cependant pas observé de modification sensible du nombre des glandes actives. L'augmentation de la sueur sécrétée provient donc d'une augmentation de la sécrétion de chacune des glandes en particulier.

     

Comparisons of eccrine sweat gland anatomy in genetic, chromosomal, and other diseases, and a suggested procedure for use of sweat gland measurements in differential diagnosis

Statistical analysis of the dimensions of microdissected eccrine sweat glands (duct length, coil volume, ratio of coil volume to duct length, and axis ratio of coil) was performed for several diseases (cystic fibrosis of the pancreas, Werdnig-Hoffmann disease, tetralogy of Fallot, chronic renal disease, and trisomies 13, 18, and 21) using both individual and grouped age-matched control patients. Duct length, coil volume, and the ratio of the two all rise with age. Eccrine gland duct length was found to be significantly large in tetralogy of Fallot and Werdnig-Hoffmann disease and small in chronic renal disease (less so in males than in females, trisomy 13 and trisomy 18). Secretory coil volume was significantly smaller than normal in trisomy 21 (Down syndrome) and in chronic renal disease, and the ratio of coil volume to duct length was low in trisomy 21 and chronic renal disease. The shape of the secretory coil (axis ratio) was possibly abnormal in trisomy 13. Gland dimensions were normal for cystic fibrosis. Using the multivariate procedure of discriminant analysis, it was found that sweat gland measures significantly contributed to the differentiation of diseases, after adjustments were made for variations in age-at-death. This suggested the possibility that criteria for distinction of clinically similar genetic, metabolic, or chromosomal diseases by study of the anatomic properties of eccrine glands obtained by skin biopsy could be developed. A procedure of analysis comparing the "percentage of normal" of gland dimensions for each disease to control values, and thereby differentiating disease categories on the basis of the "percentage of normal" values, is presented.     

The genetic differences in the microsomal activity of rats

The lipid composition and synthesis rate in liver microsomes of linear and hybrid rats are investigated. It is found that microsomes of hybrid rats had less amount and synthesis rate of phosphatidylcholine and phosphatidylethanolamine as well as nonesterified fatty acids. Linear rats differed from each other in phosphatidylinositol exchange rate. These genetic peculiarities of the microsomal lipid composition and synthesis rate can explain the experimentally determined absence of correlation between glucose-6-phosphatase activity and lipid maintenance in membranes of different genetic forms.     

Development and genetic differences of complement activity in rabbits

The ontogeny of haemolytic complement in rabbit serum and the genetic differences of the activity in five strains of adult rabbits were investigated by single radial haemolysis in gel and a microtiter method with purified complement components and the appropriate haemolytic intermediate cells. The haemolytic complement activity was found as early as the 15th day of foetal life, and increased with age reaching approximately adult level by the 120th day of life. Marked strain differences in both total haemolytic activity and C3 levels of adult rabbit sera were observed. The repeatability of haemolytic activity for an individual serum taken at different times was higher than that for C3 level was observed. An inherited complement deficiency, due to the lack of C6, was found in a strain of Angora rabbits. The genetic studies confirmed that this complement defect was transmitted as an autosomal recessive trait.     

Adenosine triphosphatase activity in the neural lobe of the bovine pituitary gland

1. Homogenates of neural lobes of bovine pituitary glands were fractionated by differential and density-gradient ultracentrifugation and the distribution of adenosine triphosphatase (ATPase) activity was studied. It was shown that all the activity was membrane-bound. 2. On the basis of ionic requirements the ATPase activity was grouped into three categories: (a) Mg²⁺-dependent, (b) Ca²⁺-dependent and (c) Mg²⁺+Na⁺+K⁺-dependent (ouabain-sensitive) ATPases. The activity in the absence of bivalent cations was negligible. The ratio between the activities of the three ATPases varied between the different subcellular fractions. 3. Preincubation of the subcellular fractions with deoxycholate increased the activity of the Mg²⁺+Na⁺+K⁺-dependent enzyme, whereas the Mg²⁺- and Ca²⁺-activated ATPases were either unaffected or slightly inhibited. Triton X-100 solubilized the Mg²⁺- and Ca²⁺-ATPases; however, the activity of the Mg²⁺+Na⁺+K⁺-ATPase was abolished by the concentration of Triton X-100 used. 4. All the subfractions displayed unspecific nucleotide triphosphatase activity towards GTP, ITP and UTP. These substrates inhibited the hydrolysis of ATP by all three ATPases. ADP also inhibited the ATPases. 5. Polyacrylamide-gel electrophoresis of extracts containing the Mg²⁺- and Ca²⁺-dependent ATPase activity solubilized by Triton X-100 revealed the presence of two enzymes; one activated by either Mg²⁺ or Ca²⁺ and the other activated only by Ca²⁺. 6. In sucrose density gradients the distribution of vasopressin was different from that of all three types of ATPases. It is therefore suggested that the neurosecretory granules do not possess ATPase activity.     

Ultrastructural localization of ouabain-sensitive, K-dependent p-nitrophenyl phosphatase activity in monkey eccrine sweat gland

We studied the electron microscopic localization of ouabain-sensitive, potassium-dependent p-nitrophenyl phosphatase (K-pNPPase) activity of the Na K-ATPase complex in Rhesus monkey eccrine sweat gland by use of the one-step lead citrate method of Mayahara et al. (Histochemistry 1980; 67:125). Reaction product was observed predominantly in the cytoplasmic side of the basolateral membranes of clear (secretory) cells, especially in the interdigitating membrane folds in the basal labryinth, and were completely abolished by 10 mM ouabain or by removal of K+. Little or no enzyme activity was noted in membrane processes in the intercellular canaliculi and in the secretory coil lumen. Basolateral membranes of the dark cells also showed moderate enzyme activity. The myoepithelial cell membrane was devoid of reaction product, except in a few membrane processes arising from the inner aspect of myoepithelial cells. In the coiled duct, K-pNPPase activity was present predominantly in the entire cell membrane of the peripheral ductal cells. The predominantly basolateral distribution of Na-K-ATPase in the eccrine sweat secretory cells is consistent with the concept that a Na-K-Cl co-transport model may be involved in the mechanism of eccrine sweat secretion.     

Development and genetic differences of complement activity in rabbits*

The ontogeny of haemolytic complement in rabbit serum and the genetic differences of the activity in five strains of adult rabbits were investigated by single radial haemolysis in gel and a microtiter method with purified complement components and the appropriate haemolytic intermediate cells. The haemolytic complement activity was found as early as the 15th day of foetal life, and increased with age reaching approximately adult level by the 120th day of life. Marked strain differences in both total haemolytic activity and C3 levels of adult rabbit sera were observed. The repeatability of haemolytic activity for an individual serum taken at different times was higher than that for C3 levels and no significant correlation between haemolytic activity and C3 level was observed. An inherited complement deficiency, due to the lack of C6, was found in a strain of Angora rabbits. The genetic studies confirmed that this complement defect was transmitted as an autosomal recessive trait.