Rana Tigrina Research Articles

Interrelationship between food availability, fat body, and ovarian cycles in the frog,Rana tigrina, with a discussion on the role of fat body in anuran reproduction

Long-term experiments were conducted to study the progression of vitellogenic cycles in Rana tigrina (an annual breeder) having different foraging backgrounds and held under conditions of weekly or daily food supply and in presence or absence of abdominal fat bodies. They were autopsied in June to assess fecundity. In nature an adult R. tigrina produces on an average 4,000 eggs/100 g body mass (b.m.) And spawns in June-July following monsoon rains. Weekly feeding from July to next breeding season, June resulted in a significant decrease in both fecundity (1700 eggs/100 g body b.m.) And mean size of eggs, compared to well-fed or wild-caught frogs. The abdominal fat bodies were barely seen in frogs fed weekly throughout, whereas in frogs fed weekly from July-December but daily from January onwards, the fat bodies became noticeable (1% of b.m.) And number and mean size of eggs increased significantly over those fed weekly throughout. Frogs captured in January possessed enlarged fat bodies (5% of b.m.), depicting a good foraging history. Maintenance of these frogs on a weekly feeding regimen led to an exhaustion of fat stores. They produced less number of eggs (2, 000/100 g b.m.) As compared to wild frogs but of normal size, whereas daily feeding slowed down a depletion of fat body mass and also significantly increased fecundity (3,000/100 g b.m.) Over the weekly fed individuals. Sham operation or fat body ablation in October or February had no significant effect on total fecundity per se (3,000-3,500 eggs/100 g b.m.) Compared to that of wild-caught frogs. However, eggs were significantly smaller due to fat body ablation despite daily feeding. The study shows that food abundance/fat bodies influence egg size and number in R. tigrina and that a direct or indirect functional relationship exists between fat body and ovarian cycles that are characteristically inverse to each other. J. Exp. Zool. 286:487-493, 2000.

Functional studies of a glucagon receptor isolated from frog Rana tigrina rugulosa: implications on the molecular evolution of glucagon receptors in vertebrates

In this report, the first amphibian glucagon receptor (GluR) cDNA was characterized from the liver of the frog Rana tigrina rugulosa. Functional expression of the frog GluR in CHO and COS-7 cells showed a high specificity of the receptor towards human glucagon with an EC 50 value of 0.8±0.5 nM. The binding of radioiodinated human glucagon to GluR was displaced in a dose-dependent manner only with human glucagon and its antagonist (des-His 1-[Nle 9-Ala 11-Ala 16]) with IC 50 values of 12.0±3.0 and 7.8±1.0 nM, respectively. The frog GluR did not display any affinity towards fish and human GLP-1s, and towards glucagon peptides derived from two species of teleost fishes (goldfish, zebrafish). These fish glucagons contain substitutions in several key residues that were previously shown to be critical for the binding of human glucagon to its receptor. By RT-PCR, mRNA transcripts of frog GluR were located in the liver, brain, small intestine and colon. These results demonstrate a conservation of the functional characteristics of the GluRs in frog and mammalian species and provide a framework for a better understanding of the molecular evolution of the GluR and its physiological function in vertebrates.

Light-induced changes in frog pineal gland N-acetyltransferase activity

N-Acetyltransferase (NAT) activity was determined in the pineal gland of frogs ( Rana tigrina) of different ages using 2-aminofluorene and p-aminobenzoic acid as substrates, and assayed by high-pressure liquid chromatography. Frogs of different ages were either killed during the light phase or exposed to darkness or light for 1 min during the dark phase of the lighting cycle, then returned to their cages in darkness for 30 min before being killed. The pineal gland NAT activity of 1-month-old frogs was inhibited when the animal was nocturnally exposed to 1 min of light. Nocturnal light exposure did not inhibit NAT activity in 1-month-old frogs, even though these animal displayed clear light-dark differences in pineal gland NAT activity. Nocturnal light exposure did not inhibit night-time levels of NAT activity in 1-month-old animals which had been bilaterally enucleated, thus suggesting that this effect is retinally mediated. Pretreatment of 1-month-old and 6-month-old animals with isoproterenol (a beta-adrenoceptor agonist drug) prevented the nocturnal light-induced inhibition of NAT activity. From the different sensitivity of 1-month-old and 6-month-old animals to different intensities or durations of nocturnal light exposure it was found that the duration or intensity of light exposure was not able to inhibit nocturnal NAT activity. The NAT activity was at least 4–5-fold greater in 1-month-old frogs than in 6-month-old frogs. This is the first demonstration of the retino-pineal gland pathway that appears to produce light-induced changes in pineal glands of frogs 1-month-old or older, but this pathway only functions in 1-month-old frogs, and does not appear to function in 6-month-old frogs.

Bioelectrical activity of brain in Rana tigrina (Daudin) in response to phosalone poisoning

An acute dose of phosalone, intraperitoneally injected to Rana tigrina alters the bioelectrical activity of the brain. The frequency levels of delta, theta, alpha, and beta waves remained similar in both control and experimental groups, while the amplitude of the waves was significantly decreased by 40 to 60% in the latter group. The total work done (TWD) was also significantly reduced. The above disturbance in the brain electrical activity may have correlation to the inhibition of cation-linked ATPase, as well as the cholinesterase activity.

Role of Temperature and Photoperiod in the Onset of Sexual Maturity in Female Frogs, Rana cyanophlyctis

Role of Temperature and Photoperiod in the Onset of Sexual Maturity in Female Frogs, Rana cyanophlyctis

Calcitonin-like immunoreactivity in the subcommissural organ and Reissner's fiber in the teleost Clarias batrachus, frog Rana tigrina and lizard Calotes versicolor

In the CNS of vertebrates, although the subcommissural organ (SCO) has been identified as an ependymal brain gland and Reissner's fiber (RF) as a condensed product of its secretion, the exact nature of the secretory substances has remained elusive. In the present study, immunocytochemical application of polyclonal antibodies against calcitonin revealed intense immunoreactivity in the cells, cell processes and cerebrospinal spinal fluid (CSF)-contacting apical terminals of the columnar ependymal cells of the SCO in the teleost, Clarias batrachus. Intense immunoreactivity was also seen throughout the length of the RF as it extended along the Sylvian aqueduct, fourth ventricle and central canal of the spinal cord. Control procedures were employed to confirm the specificity of the immunoreaction. The results for the first time suggest that calcitonin-like substance may be the synthetic and secretory product of the SCO that may be released into the CSF or stored in the RF. Presence of calcitonin-like immunoreactivity in the SCO-RF complex of the frog Rana tigrina and the lizard Calotes versicolor underscores wider significance of the phenomenon. In view of the potentials of these findings, it is felt that investigations aimed at establishing the precise nature of calcitonin-like immunoreative material in the SCO-RF complex may be rewarding. © 1997 Elsevier Science B.V. All rights reserved.

Long-Term Effects of Ovariectomy on Abdominal Fat Body and Body Masses in the Frog Rana tigrina during the Recrudescent Phase

Long-Term Effects of Ovariectomy on Abdominal Fat Body and Body Masses in the Frog Rana tigrina during the Recrudescent Phase

Induction of ovarian follicular development in the subadult frogRana tigrina using luteinizing hormone releasing hormone-acetate

In the subadult Rana tigrina administration of 2 µg luteinizing hormone releasing hormone-acetate/frog six days a week for 4 weeks in April resulted in the formation of medium (in all 8 frogs) and large sized (in 4 out of 8 frogs) yolky oocytes and, concomitant increases in the oviductal mass. The ovarian and oviductal masses showed a 10-fold increase over the control frogs. In untreated frogs the ovaries were transparent and contained first growth phase oocytes only. The oviducts were also infantile. The pituitary sections were stained using antisera raised in rabbit against the β-subunit of human luteinizing hormone and human follicle stimulating hormone. Immunoreactivity, staining intensity, cytoplasmic granulation and, cell, nuclear and cytoplasmic areas of gonadotrophs (B2 cells) increased significantly in luteinizing hormone releasing hormone treated frogs. The above findings suggest that pituitary-ovarian axis in the subadult Rana tigrina is responsive to luteinizing hormone releasing hormone and that long-term treatment with the hormone induces cytomorphological changes in the gonadotrophs which result in the conversion of inactive cells into secretory cells. This is accompanied by precocious vitellogenic growth of oocytes in the subadult frogs.

Phosalone poisoning on the cation-linked ATPases of central nervous system of Rana tigrina (Daudin)

An acute dose of phosalone, an organophosphate pesticide, widely used in crop fields, injected to Rana tigrina, intraperitoneally, inhibited the different inorganic ion linked ATPase enzymes of the central nervous system (CNS). Six discrete CNS compartments, namely telencephalon, mid-brain, rhombencephalon, cervical spinal cord, thoracic spinal cord and lumbar spinal cord showed markedly diminished ATPase activity. ATPases inhibition affected the neuronal activity and muscular coordination leading to moribund or comatose phase in the poisoned frogs. The specific inhibition of Mg 2+-ATPase suggests the uncoupling action of the compound in the neuronal tissue. Increased oxygen uptake in the brain regions of phosalone-treated frogs also supports the above uncoupling action.

Advertisement calls of two anuran amphibians,Rana tigrina andTomopterna breviceps

Rana tigrina andTomopterna breviceps occur as sympatric species at Dharwad, India. Sexually mature males produce advertisement calls. The advertisement call of both the species consist of a number of calls produced in series forming a call group. Each call group ofRana tigrina comprises 10–40 calls, whereas that ofTomopterna breviceps consists 13–141 calls. Each call consists of a pulse group with variable number of pulses which lack pulse interval. Calls of both the species exhibit similarities in (i) call consisting of series of calls with a pulse group in each call, (ii) absence of pulse interval within the pulse group, (iii) the amplitude of the first pulse being always small, and (iv) the frequency spectrum beginning from 200 Hz. Based on the similarities in the spectral features of the calls, it is suggested that the two species may be closely related to each other.

The Cardiovascular and Renal Effects of Hydrins and Arginine Vasotocin in Frogs

Cardiovascular and renal actions of hydrins and arginine vasotocin (AVT) in frogs ( Rana tigrina and Rana catesbeiana) were examined in view of their relationships as precursor/ prohormone-hormones in the anuran amphibian. In vitro hydrins and AVT respectively vasorelaxed and vasoconstricted KCl-preconstricted femoral artery in R. tigrina. AVT also produced dose-dependent contractions on untreated preparations; hydrins had no effect on these preparations. Both the hydrins and AVT were positively inotropic and chronotropic, with AVT being more potent. In vivo hydrins and AVT were anti-diuretic except at high doses, when AVT became diuretic. The hydrins and AVT were vasodepressor and pressor, respectively, in R. catesbeiana. These data suggest that the addition of one to three amino acids onto the AVT molecule reverses the contractile response in the vascular smooth muscle. With this dissociation of the vascular effect from that of the renal, the hydrins might play a physiological role in water balance of frogs.

Studies on the life-cycle of Tremiorchis ranarum

AbstractThe life-cycle of Tremiorchis ranarum Mehra and Negi, 1926 (Trematoda: Plagiorchiidae) infecting Rana tigrina and R. cyanophlyctis is elucidated. Life-cycle stages, from egg to egg-producing adults, were successfully established in the laboratory. Life-cycle took more than two months for completion. Cercariae were found in the snail, Pila virens collected from paddy fields at Chelembra in the Malappuram district of Kerala during the monsoon months. Cercariae are of the xiphidiocercous type. Metacercariae occurred beneath the skin and in head, tail and body musculature of tadpoles of R. tigrina and R. cyanophlyctis. Adult frogs are refractory to cercarial infection. Frogs became infected when they fed on tadpoles containing metacercariae. Successive stages in the development to adult from the metacercariae were followed. Chronological synchronization in the reproductive activity of the host and the parasite is briefly discussed.

Distribution of corticotropin-releasing factor immunoreactive neurons in the brain of the tigerfrog, Rana tigrina

The distribution of immunoreactive (ir) neurons containing corticotropin-releasing factor (CRF) is described in the brain of the tigerfrog, Rana tigrina. The olfactory bulb, medial pallium, nucleus of the diagonal band of Broca and medial area of the amygdala of the telencephalon showed ir-CRF perikarya. The anterior and ventromedial thalamic nuclei, and the magnocellular nucleus preopticus (NPO) revealed several ir cells; a few NPO neurons were cerebrospinal fluid contacting in nature. The nucleus hypothalamicus ventromedialis contained a few cells, but the nucleus infundibularis ventralis of the infundibulum revealed several diffusely distributed perikarya. Individual ir-CRF perikarya were visualized in the optic tectum and interpeduncular nucleus. Extensive fiber terminals were present in the median eminence, but no fibers were discerned either in the neural lobe or in the pituitary gland.

Cardiac activity of some peptide hormones in the frog, Rana tigrina

1. The cardiac responses of isolated frog ( Rana tigrina) atria to peptide hormones were studied. 2. Calcitonin gene-related peptide (CGRP), arginine vasotocin (AVT), bovine parathyroid hormone fragment (bPTH-(1–34)) and oxytocin (OXY) produced dose-related positive chronotropic and inotropic responses; atrial natriuretic peptide (ANP) was negative chronotropic and inotropic; cholecystokinin (CCK), vasoactive intestinal peptide (VIP) were without effects. 3. The dose-related responses under bPTH-(1–34) stimulation but not CGRP or AVT were attenuated in the presence of ANP (300 ng/ml, ≈0.98 × 10 −7 M). As expected ANP decreased the basal AR and AT responses of the isolated atria and the inhibitory effects were dose-dependent. 4. As shown previously, propranolol blocked the atrial tension stimulated by bPTH (1–34) but did not alter the cardiac responses to CGRP and AVT. 5. In the presence of β-adrenergic blocker (propranolol 10 −7M) or ANP (10 −7M), the AR and AT changes under ISO stimulation in the frog were also decreased. 6. These cardiac changes suggest the cardiac inhibitory effects of ANP are related to β-adrenoceptor activity and ANP might be a β antagonist.

Influence of Tadpole Movement on Predation by Odonate Naiads

, N. U. BHUTTEWADKAR, AND C. R. HIREMATH. 1990. Onset of breeding season in some anuran amphibians of Dharwad, Karnataka. J. Bombay Nat. Hist. Society 87:156-157. KURIAN, T., AND S. K. SAIDAPUR. 1983. Frequency distribution of cell numbers in the spermatocysts during the annual testicular cycle in the Indian frog Rana tigrina. J. Herpetol. 17:315-319. LOFTS, B. 1984. Reproductive cycles of vertebratesamphibians. In G. E. Lemming (ed.), Marshall's Physiology of Reproduction, pp. 127-205. Churchill Livingstone, London. MIZELL, S. 1965. Seasonal changes in energy reserves in the common frog Rana pipiens. Cell Physiol. 66: 251-258.

Cardiac activity of calcitonin gene-related peptide in amphibian species ( Rana tigrina, Triturus SP.)

1. 1. Calcitonin gene-related peptide (CGRP) produced dose-related positive chronotropic and inotropic responses in isolated atria of a newt, Triturus sp. and a frog, Rana tigrina. It was apparent that CGRP was stimulatory on the heart of the amphibian species. 2. 2. In the frog, these dose-related responses were attenuated in the presence of a CGRP antagonist (hCGRP 3 × 10 −8M). This was indicative of the presence of cardiac CGRP receptors. 3. 3. In the presence of β-adrenergic (propranolol 10 −6M) and calcium channel (verapamil 10 −8M, but not nifedipine 10 −8M) blocker, the basal AR in the frog were decreased. AR induced by CGRP were increased however. 4. 4. The maximal AR and AT responses of the isolated atria to CGRP were not affected by the presence of propranolol. 5. 5. In the presence of calcium channel blockers (verapamil and nifedipine), the maximal AT response was attenuated. These changes suggest the cardiac effects of CGRP are related to calcium mobilization.

Studies on the life-cycle of Pleurogenoides ovatus Rao, 1977 (Trematoda: Pleurogenetinae)

The life-cycle of Pleurogenoides ovatus Rao, 1977, infecting the frogs, Rana tigrina and R. cyanophlyctis has been elucidated. All the life-cycle stages from egg to egg-producing adults were successfully established in the laboratory. The life-cycle took about 80 days for completion. Cercariae were found in the freshwater snail. Digoniostoma pulchella, collected from paddy fields at Chelembra, Malappuram district of Kerala, during the monsoon months. Cercariae are of the virgulate xiphidiocercous type. Metacercariae occurred in the connective tissues, hepatopancreas and musculature of the freshwater crab, Paratelphusa hydrodromous. The growth and development of the metacercariae in P. hydrodromous have been studied in detail. Frogs became infected when they fed on infected crabs. The prepatent period is 10 days.

Cardiovascular effects of bPTH-(1–34) and isoproterenol in the frog, Rana tigrina

1. The cardiovascular effects of bovine parathyroid hormone fragment [bPTH-(1–34)] and isoproterenol (ISO) on frog ( Rana tigrina) isolated atria and helical strips of blood vessels were examined since PTH produces a β-adrenergic-like effect in the mammal. 2. Data showed that both bPTH-(1–34) and ISO were vasorelaxant in KC1 and arginine vasoctocin (AVT) preconstricted dorsal aorta, iliac and femoral arteries. 3. They both relaxed extracellular calcium-dependent contrations. 4. There was no additive nor synergistic effect between them in AVT preconstricted strips. 5. Both bPTH-(1–34) and ISO were positively inotroplc but differed in their chronotroplc effects, being negative and positive. 6. In the tiger frog, bPTH-(1–34) shows β-adrenergic like contractile responses in both the cardiac and vascular smooth muscle as in the mammal, but not in the heart rate.

The response of nucleus preoticus neurosecretory cells to ovarian pressure in the frog, Rana tigrina

Intraovarian pressure (IOP) of 5, 15, and 25 mm Hg was administered in the frog, Rana tigrina, and the response of the nucleus preopticus (NPO) pars magnocellularis was investigated with aldehyde fuchsin (AF) stain and immunocytochemical method using neurophysin (NP) antisera. The 5 mm Hg IOP treatment resulted in cell and cell nuclear hypertrophy ( P < 0.001); discrete signs of de novo synthesis of AF-positive and NP-immunoreactive material in the perikarya and remarkable increases in the number and size of “Herring bodies” in the processes were observed. Stimulatory response after 15 mm Hg IOP treatment was characterized by dramatic augmentation of the AF-positive and NP-immunoreactive material in the processes; the engorged and coalescing Herring bodies totally predominated the lateral preoptic area. IOP of 25 mm Hg resulted in extensive loss of secretory material; the processes revealed the presence of vacuoles indicative of the rapid anterograde transport of the neurosecretory material. Furthermore, the application of IOP seemed to promote the transport of NP-immunoreactive material toward the anterior preoptic area and amygdala pars medialis and the release of secretory material into the cerebrospinal fluid. No changes were observed in the NPO when treatment was preceded by the transection of ipsilateral dorsal spinal nerve roots or the spinal cord. The results suggest the existence of an afferent neural pathway from the ovary capable of conducting the stretch signals to the NPO and triggering the synthesis and release of neurohypophysial hormones.

Neurohypophysial hormones and cardiac activity in the frog, Rana tigrina, and in the snake, Ptyas mucosa

The cardiac effects of neurohypophysial hormones (NH) in the frog, Rana tigrina, and in the snake, Ptyas mucosa, were studied in isolated atrial preparations. Arginine vasopressin (AVP), vasotocin (AVT), isotocin (ISN), mesotocin (MSN), and oxytocin (OXY) produced dose-related positive chronotropic and inotropic responses in the frog atria. AVT was the most potent. In the snake, AVP, AVT, MSN, and OXY produced dose-related positive inotropic but not chronotropic changes. OXY was the most potent. Data indicate that there is a direct action of NH on the heart in both animals, the atrial rate and tension responses to NH are not coupled, and judging by the efficacy, AVT and OXY might be the natural NH in the frog and snake, respectively, which may account for the high concentrations required of other NH to be cardiac stimulating.