Ophelia Gona

Mucous glycoproteins of teleostean fish: a comparative histochemical study.

SynopsisTo examine the hypothesis that the histochemical characteristics of teleostean mucus reflect functional characteristics, mucous cells were studied in four related and behaviourally similar species of fish (Family Belontidae). Histochemical characteristics were determined with Alcian Blue at both pH 2.6 and pH 1.0 followed by the periodic acid-Schiff technique. It was found that the four species differed in glycoprotein type as well as in number of mucus-containing cells. The differences are ciscussed in regard to functional characteristics and environmental influence.

Failure of synthetic TRF to elicit metamorphosis in frog tadpoles or red-spotted newts☆

Abstract Synthetic TRF was administered intraperitoneally to bullfrog tadpoles (40 μg per day per animal of 16- to 18 g body weight) and red efts (20 μg per day per animal of 1.0- to 1.2g body weight). No indication of metamorphosis-stimulating effect was elicited in either of these amphibian species.

Effects of prolactin and thyroxine in hypophysectomized and thyroidectomized red efts of the newt Notophthalmus (Diemictylus) viridescens

Abstract In an earlier investigation of the role of hormones on the second metamorphosis of intact newts, we unexpectedly found that small doses of thyroxine (T 4 ) act synergistically with prolactin. The present report presents evidence which seems to establish the existence of such a synergism. Hypophysectomized-thyroidectomized (HX-TX) red efts were injected on alternate days with 0.01 ng T 4 and 0.25 unit of ovine prolactin. This treatment brought about second metamorphorsis, including spontaneous migration of all the animals into water (100% water drive), by day 10. In contrast, only 10% of HX-TX efts treated with prolactin alone showed water drive, and 90% retained their rough skin; all died by day 10. As for the intact animals treated with only prolactin, 30% showed water drive during the same period.

Calcaneal Spurs in a Black African Population

The radiological incidence of calcaneal spurs in a black African population was studied. Our findings show that spur incidence increased with age and was greater in females than in males. These results, the first from a large, exclusively African population, are similar to those from previous studies of individuals from other continents.

Pharmacodynamics of Alcide, a New Antimicrobial Compound, in Rat and Rabbit

Alcide is a germicidal preparation which has been shown to kill a wide range of common pathogenic bacteria as well as fungi, in vitro. This preparation is composed of Part A and Part B which contains sodium chlorite (NaClO2) and lactic acid as the active ingredients, respectively. The two parts are combined in equal volumes immediately prior to application resulting in the formation of chlorine dioxide (ClO2). Alcide gel was applied to the shaven backs of 18 female Sprague-Dawley rats in a 2.0-g/kg dose by combining 1 g of each part immediately prior to administration. This dose was applied for a period of 10 days to reach a steady state. On the 11th day, 36Cl-labeled Alcide gel, which contained Na36ClO2 in Part A, was administered to the animals in a 0.6-g dose (2.0 g/kg) containing 0.1 microCi. The half-life for 36Cl absorption was 22.1 hr while the elimination half-life was 64.0 hr. 36Cl was excreted by the kidneys with chloride (Cl-) and chlorite as the metabolites. Ninety-six hours after Alcide administration, radioactivity was highest in whole blood and lowest in fat. In a 90-day subchronic dermal toxicity study in rabbits, exposure to Alcide gel resulted in decreased glutathione concentrations in blood of the group receiving 2.0 g/kg Alcide as well as in the placebo gel group which received the same dose of gel.

Toxic effects of mammalian prolactin on Colisa lalia and two other related teleostean fish

Abstract Mammalian prolactin has been found to have a highly toxic effect on certain teleostean fish. The effect is not due to contamination by growth hormone or ADH, nor is the toxic factor removed by dialysis. The toxic effect is dependent upon type and activity of the prolactin as well as upon the species, and perhaps the size, of the fish. Possible reasons for the toxic action are discussed.

Local action of thyroxine implants on cerebellar maturation in frog tadpoles

Abstract Implants of a mixture of thyroxine and cholesterol (1 : 10) or of cholesterol alone were placed in the fourth ventricle of bullfrog tadpoles. Fourteen days after surgery, the brains of all tadpoles were processed for light microscopic examination. The cerebella of the control tadpoles, with implants containing only cholesterol, showed no indication of any maturational changes. The cerebella of the tadpoles with thyroxine-containing implants, on the other hand, showed advanced maturational changes, although no external metamorphic changes were exhibited by these animals. It is concluded that thyroxine induces cerebellar maturation by direct action on this part of the brain.

Localization of prolactin uptake by the kidney of the teleostean, Colisa lalia

Although evidence has been presented that the hormone prolactin specifically bind to the kidneys of the teleost Sarotherodon mossambicus (J. N. Fryer, 1979, Gen. Comp. Endocrinol. 39, 397-403.) prolactin has not previously been shown to become localized at any particular morphological sites in fishes. This problem has been investigated in the dwarf gourami, Colisa lalia. Ovine prolactin was labeled with (125)I and injected intramuscularly. Fish were sacrificed after 15, 30, and 90 min. Other animals were injected with an excess of unlabeled prolactin, growth hormone, or luteinizing hormone 2 min prior to administration of the label. Paraffin-embedded tissues were sectioned, coated with Kodak NTB-3, and exposed for 3-5 weeks. After developing, samples of several body tissues were stained and examined for the presence of silver grains. The results indicate that, as in rat and frog, kidney tubules of C. lalia are sites of prolactin localization. No other sites of prolactin localization were identified.

Cytoarchitectural changes in lens epithelium of galactose-fed rats

Whole mounts of lens epithelia from rats fed on a galactose-rich diet for one, two, three or seven days were examined for morphological alterations. The meridional rows of epithelia from lenses of animals fed on galactose for seven days were found to be grossly disorganized or abnormally elongated. There was some indication that the cells were edematous and that the epithelium had become multilayered. These abnormalities apparently extended into the transitional zone. Evidence of the cytoarchitectural changes was present as early as one day after institution of the 30% galactose diet and progressed steadily over the period of observation. The findings provide support for the hypothesis that loss of meridional row integrity is a phenomenon common to development of most types of cortical cataracts.

Prolactin and ergocryptine effects on mucus glycoproteins of the rat ileum.

SummaryThe present work reports observations from a first study on the effect of prolactin on mucous cells of the mammalian ileum. Sprague-Dawley rats were treated with prolactin or with the prolactin-inhibitor ergocryptine. Light microscopic histochemical study revealed that ergocryptine increased the number both of Alcian Blue-positive mucous cells and of the total number of mucous cells in the ileal crypts. Prolactin treatment apparently decreased the number of Alcian Blue pH 1.0-positive (sulphated glycoprotein-containing) mucous cells on the villi but was without effect on crypt cells. The implications of these observations are discussed.