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Biomedical subjects

V May

Publications and source records attributed to V May.

15 recordsLinked to original sources
PubMed1992

Galanin-like innervation of rat submandibular and sublingual salivary glands: origin and effect on acinar cell membranes.

The distribution and source of a galanin-like innervation of rat salivary glands has been examined. Additionally, submandibular and sublingual acinar cell membrane responses to galanin or a cholinergic agonist were studied. Galanin-immunoreactive fibers were observed throughout the submandibular and sublingual glands in association with ducts and acini. A subset of submandibular ganglion cells expresses galanin immunoreactivity. Parasympathectomy resulted in a marked decrease in galanin immunoreactivity in the glands. Sympathectomy resulted in marked reduction of dopamine beta-hydroxylase immunoreactivity with no appreciable change in galanin immunoreactivity. Retrograde labeling experiments demonstrated that galanin-immunoreactive sensory neurons in the trigeminal ganglion do not innervate the submandibular or sublingual gland. These results indicate that the galanin-like innervation of rat salivary glands is derived from parasympathetic nerves to the glands. Since rat sublingual glands contain largely mucous acini while rat submandibular gland acini are seromucous, electrophysiological responses to galanin and the muscarinic agonist, bethanechol, were compared. Agonist-induced voltage shifts varied between the two glands. The galanin-induced response at the level of the resting membrane potential in submandibular acinar cells was a hyperpolarization, while that in sublingual acinar cells was a depolarization. There was also a greater voltage dependence to the galanin-induced submandibular response than to the sublingual response. Differences were also noted in the acinar cell response to cholinergic stimulation between these glands. These results demonstrate the existence of a galanin-like innervation to salivary glands that may be functionally relevant. Moreover, the results challenge the idea that agonist-induced membrane responses are similar among acinar cells of different glands.

Animals↗
PubMed1992

Expression of peptidylglycine alpha-amidating monooxygenase: an in situ hybridization and immunocytochemical study.

Peptide alpha-amidation, an essential posttranslational modification that confers bioactivity to many neuroendocrine peptides, is catalyzed by peptidylglycine alpha-amidating monooxygenase (PAM; EC 1.14.17.3). To complement our previous studies on the distribution of PAM in neuroendocrine organs, we have examined expression of the PAM gene in several endocrine tissues by in situ hybridization and immunocytochemistry. In all instances, the autoradiographic densities for PAM mRNA correlated with staining patterns for PAM immunoreactivity. Very high levels of PAM mRNA were found in all heart atrial cardiomyocytes, while much lower levels were present in ventricular cells. In the sublingual gland, PAM was expressed diffusely in both acinar and tubule cells. In contrast, expression of PAM was confined to granular convoluted tubule cells in the submaxillary gland. PAM was expressed at high levels in a subset of adrenal medullary chromaffin cells, and low levels of PAM mRNA and immunoreactivity were also detected in the adrenal cortex. PAM was found predominantly in the calcitonin-producing parafollicular C-cells in the thyroid gland and in the glucagon-containing A-cells in the endocrine pancreas. Collecting and distal tubule cells of the kidney expressed both PAM mRNA and immunoreactivity. The basal cells in testicular seminiferous tubules containing PAM may represent developing germ and Sertoli cells. The cellular localization of PAM within the thyroid gland, adrenal gland, testis, and pancreas correlated with known peptidergic systems, and some of the observed cellular heterogeneity in PAM mRNA expression and immunoreactivity may reflect differences in the levels of amidated peptide production. The expression of PAM in cells not known to produce high levels of alpha-amidated peptides may indicate the production of yet unidentified alpha-amidated bioactive peptides or alternative functions of the PAM protein.

Adrenal Medulla↗
PubMed1990

Thyroid hormone regulation of peptidylglycine alpha-amidating monooxygenase expression in anterior pituitary gland.

Peptidylglycine alpha-amidating monooxygenase (PAM; EC 1.14.17.3) is a copper-, molecular oxygen-, and ascorbate-dependent enzyme which catalyzes the COOH-terminal amidation of bioactive peptides. Expression of PAM in the adult male rat anterior pituitary was evaluated after experimental manipulation of thyroid status. Levels of PAM mRNA increased 4- to 7-fold in animals made hypothyroid by treatment with 6-n-propyl-2-thiouracil or thyroidectomy and were not diminished below control levels in animals made hyperthyroid by treatment with T4. Treatment of thyroidectomized animals with T4 prevented the increase in PAM mRNA levels; similar doses of T4 returned serum TSH and anterior pituitary PAM mRNA to euthyroid values. Based on Northern blot analysis and amplification of fragments derived from rat PAM-1 by reverse transcription and the polymerase chain reaction, thyroid status did not affect the distribution of PAM mRNA among its various alternatively spliced forms. The specific activity of PAM in the anterior pituitary was increased slightly in both the soluble and particulate fractions from chemically hypothyroid rats; the majority of the PAM activity in the rat anterior pituitary was soluble, and increased secretion of enzyme may account for the lesser effect of chemical thyroidectomy on specific activity compared to mRNA levels. Western blot analysis demonstrated a 104-kDa PAM protein in particulate fractions prepared from control, PTU-treated, and T4-treated animals. The soluble fraction contained major PAM proteins of 95 and 75 kDa, and PTU treatment brought about an increase in the prevalence of the 75-kDa form of PAM protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1975

[The cardiovascular manifestations of Paget's disease].

After reviewing the old ideas (peripheral syndrome and cardiac insufficiency at high outputs) and more recent ideas (arterial and intracardiac vascular calcification), the authors report their experiences based on the study of the histories of 150 patients suffering from Paget's disease followed for several years. First they emphasize the frequent latency of cardiac manifestations looked for systematically by means of the electrocardiogram particularly during evolutive stages of the disease. Electrocardiographic disturbances were observed 91 times and included 43 cases of conduction disorders and 48 of repolarization disorders; their distribution was studied as a function of various inherent parameters, of the patient (age and sex) and of the disease (its evolutive character and its degree of diffusion). On the basis of the anti-arythmic power of calcitonin found during experiments and obtained excellent results three times. Finally the place of cardiovascular manifestations in the pathogenic hypotheses and nosology of Paget's disease is discussed.

Adult↗
PubMedDate not supplied

[Coronary insufficiency in patients with gout].

Statistics on the frequency of coronary insufficiency in patients with gout are contradictory. Nevertheless, it is shown that a correlation often exists between attacks of gout and attacks of angina or acute ischaemic episodes. Finally, these anatomo-clinical studies prove the reality of the gouty heart if only because of the discovery of deposits of intracardiac urates.

Adenosine Diphosphate↗