Gunderao K. Kulkarni

In vivo stimulation of ovarian development in the red swamp crayfish, Procambarus clarkii (Girard), by 5-hydroxytryptamine

Summary The possibility that biogenic amines affect ovarian development in the red swamp crayfish, Procambarus clarkii, was investigated. Females were administered 15 μg/g body weight (bw) of norepinephrine, dopamine, 5-hydroxytryptamine (5-HT) or octopamine on days 1, 5 and 10 and were sacrificed on day 15. Crayfish given 5-HT showed significant increases in ovarian index (30.5%) and oocyte size (34.0%) over the concurrent controls, while norepinephrine, dopamine and octopamine did not significantly affect either the ovarian index or oocyte size. Significantly more labeling by 14C-leucine of ovarian proteins was found in ovaries of crayfish that were injected with 5-HT in vivo, but when ovarian lobes from crayfish that had not been injected with 5-HT were incubated in vitro with 5-HT added to the incubation medium, no significant change in the level of incorporation of 14C-leucine into ovarian proteins occurred. The 5-HT receptor blocker LY53857 (25 μg/g bw) retarded ovarian development. The 5-HT release...

Oogenesis and Effects of Neuroendocrine Tissues on in Vitro Synthesis of Protein by the Ovary of the Red Swamp Crayfish Procambarus Clarkii (Girard)

ABSTRACT In the red swamp crayfish Procambarus clarkii oocyte development was classified into seven stages according to morphological characters: (1) oogonial (< 10 μm), (2) immature (10-65 μm), (3) avitellogenic (66-160 μm), (4) early vitellogenic (161-245 μm), (5) midvitellogenic (246― 455 μm), (6) late vitellogenic (456-980 μm), and (7) postvitcllogenic and resorptive. Stage 1 (oogonial) is a multiplication stage, and oocyte maturation occurs in stages 2-6. Follicle cells become arranged around the oocytes in stage 3. Stages 4, 5, and 6 are the yolk granule development stages, with strongly acidophilic yolk granules accumulating in the cytoplasm. Yolk granules first appear at the periphery and then gradually spread throughout the cytoplasm. The ovarian index increases steadily up to stage 6, but in stage 7 the ovarian index decreases. The incorporation of 14C-leucine into ovarian or oocyte proteins occurs throughout vitellogenesis. When ovarian tissue was incubated with the eyestalk neuroendocrine tissues, leucine incorporation was inhibited, whereas when other neuroendocrine tissues, brain, subesophageal ganglion, or thoracic ganglia, were added to the incubation medium, leucine incorporation into ovarian proteins increased significantly. The inhibition produced by the eyestalk tissues was presumably due to the well-documented ovary-inhibiting hormone, whereas the stimulation produced by the other organs was presumably due to an ovary-stimulating hormone.

Localization of substance P-like, leucine-enkephalin-like, methionine-enkephalin-like, and FMRFamide-like immunoreactivity in the eyestalk of the fiddler crab, Uca pugilator

SummaryThe occurrence and distribution of substance P (SP)-like, methionine-(Met)- and leucine-(Leu)-enkephalinlike, and FMRFamide-like immunoreactivities were determined in the neuroendocrine complex of the eyestalk of the fiddler crab, Uca pugilator, by immunocytochemistry. SP-like immunoreactivity was found in the optic peduncle, sinus gland, medulla externa, medulla interna, lamina ganglionaris, and retinular cells. Met-enkephalin-like and Leuenkephalin-like immunoreactivity was observed in most of the retinular cells, optic peduncle, sinus gland, medulla terminalis, and lamina ganglionaris. However, Met-enkephalin-like, but no Leu-enkephalin-like, immunoreactivity was seen in the medulla terminalis X-organ. FMRFamide-like immunoreactivity could be seen in all parts of the eyestalk except in the sinus gland, lamina ganglionaris, and retinular cells. FMRF-amide-like activity was especially strong in the three chiasmatic regions connecting the optic ganglia. The possibility that these four peptides may function as neuroregulators in the fiddler crab is discussed.

Distal retinal pigment of the fiddler crab, Uca pugilator: Evidence for stimulation of release of light adapting and dark adapting hormones by neurotransmitters

Abstract 1. 1. In intact fiddler crabs, Uca pugilator , norepinephrine (NE) produced light adaptation of the distal retinal pigment whereas dopamine (DA) produced dark adaptation of this pigment. 2. 2. Presumably, NE stimulated release of distal retinal pigment light adapting hormone whereas DA released distal retinal pigment dark adapting hormone. 3. 3. NE appeared to produce its effect by activation of alpha 1 postsynaptic adrenoceptors. 4. 4. Pandalus red pigment concentrating hormone produced dark adaptation of the distal retinal pigment.

Quantitative Analysis by Reverse Phase High Performance Liquid Chromatography of 5-Hydroxytryptamine in the Central Nervous System of the Red Swamp Crayfish, Procambarus clarkii

The concentrations of 5-hydroxytryptamine (5-HT) in central nervous organs of the red swamp crayfish, Procambarus clarkii, were determined by reverse phase high performance liquid chromatography (RPHPLC) with electrochemical detection. The quantity ranged between 54 and 168 pg/mg wet weight of tissue. The amount is highest in the brain, followed in decreasing order by the thoracic ganglia, subesophageal ganglion, eyestalks, and abdominal nerve cord. Significant increases in the levels of 5-HT in the eyestalks, brain, subesophageal ganglion, and thoracic ganglia occurred in crayfish exposed for three days to continuous light on a white background, whereas the 5-HT levels in these tissues decreased in crayfish kept in darkness. Electrical stimulation of central nervous organs in vitro produced significant decreases in the levels of 5-HT. Fenfluramine (5-HT releaser), 5,6-DHT (5-HT neurotoxin), and reserpine (5-HT depletor) induced significant decreases in the 5-HT levels in the portions of the central nervous system tested.

Quantitative measurement by reverse phase high performance liquid chromatography of norepinephrine in the central nervous system of the red swamp crayfish, Procambarus clarkii and physiologically and pharmacologically induced alterations

1. Norepinephrine (NE) in central nervous organs of the red swamp crayfish, Procambarus clarkii, was measured by reverse phase high performance liquid chromatography, with an electrochemical detector. The concentration was highest in the eyestalks, followed in decreasing order by the brain, subesophageal ganglion, thoracic ganglia and abdominal nerve cord. 2. NE increased in these five tissues in crayfish exposed 3 days to constant light on a white background, but decreased in crayfish in darkness. 3. Bilateral eyestalk ablation in NE increases in the brain, subesophageal ganglion and thoracic ganglia. 4. Reserpine, chlorpromazine and 6-hydroxydopamine decreased NE in the five central nervous organs tested.

Chromatophorotropic activity of extracts of the brain and nerve cord of the leech, Macrobdella decora, in the fiddler crab, Uca pugilator: An in vivo and in vitro study

Abstract 1. 1. Extracts of the brain and nerve cord of the leech, Macrobdella decora , that were injected into intact fiddler crabs, Uca pugilator , produced dispersion of the pigment in the erythrophores of these crabs, but did not cause the pigment in their melanophores to disperse. 2. 2. When these extracts of leech organs were injected into isolated crab legs, there was no significant pigment dispersing effect on the erythrophores or melanophores. 3. 3. A substance, presumably 5-hydroxytryptamine, present in the central nervous system of the leech apparently stimulated the release of red pigment dispersing hormone in the crabs.

Release of black pigment-dispersing hormone and distal retinal pigment light-adapting hormone upon electrical stimulation of the isolated eyestalk neuroendocrine complex of the fiddler crab, UCA pugilator

Abstract 1. Pretreatment of isolated eyestalk tissues of the fiddler crab, Uca pugilator, with drugs that interfere with norepinephrinergic neurotransmission, alpha-methyl-p-tyrosine, fusaric acid, 6-hydroxy-dopamine, and bretylium, prior to electrical stimulation resulted in the release of significantly less black pigment-dispersing hormone (BPDH) and light-adapting hormone (LAH) than from tissues that had been kept in saline alone prior to being electrically stimulated. 2. These data support the hypothesis that norepinephrine has a physiological role in stimulating release of BPDH and LAH in the fiddler crab.

Effects of two tranquilizers, reserpine and chlorpromazine, on neurosecretory cells and the ovary of the fiddler crab, Uca pugilator

Reserpine produced alterations in neurosecretory cell types I and II in the eyestalk, brain, and thoracic ganglion, most notably a decrease in the amount of stored neurosecretory material. The ovarian index decreased, but the oocyte area increased in the reserpinized crabs. Chlorpromazine did not produce any significant changes in the structure of cell types I and II. In spite of having a normal area, the oocytes in the chlorpromazine injected crabs were devoid of yolk. Neurosecretory cell type III showed no change.