Hormonal control of blood chloride in the marine pulmonate,onchidium verruculatum

A search for endocrinological factors inO. verruculatum revealed that three hours after right pleural ganglion extirpation blood chloride is significantly (P<0.01) sinked. Administration of right pleural ganglion homogenate (I gang/animal) into depleuralised snails significantly (P<0.001) enhances the blood chloride level after three hrs. Removal of the ganglia other than the right pleural provokes a significant (P<0.01) decline in blood chloride profile in these animals. However, replacement therapy either via homogenate injection or reimplantation of the particular ganglion into extrapleural ganglionectomised animals is ineffective in restoring the chloride levels. It is argued that only right pleural ganglia control blood chloride via vascular channels.     

Seasonal variation in the biochemical composition of Mytilus viridis at Ratnagiri on the West Coast of India

1. The seasonal variation in the water, protein, fat and glycogen contents of the mussel, Mytilus viridis has been studied for the year March, 1974 to March, 1975.
2. The water level increased during the monsoon season and decreased in summer.
3. The level of protein, fat and glycogen showed correlation with the reproductive cycle of the mussel.
4. The protein level was high when the mussels were mature and dropped during the breeding period.
5. During sex change from male to female in May the protein level remained high whereas during sex change from female to male in October and November it was low.
6. The fat level was high in mature mussels and declined on spawning.
7. The glycogen level was at its peak in immature mussels and low in mature.

     

Susceptibility of urea and uric acid levels to neurohormone influence in the freshwater pulmonate,lymnaea acuminata

Effects of pooled ganglionic extract on the urea and uric acid levels from blood, hepatopancreas, mantle and kidney of the pulmonate L. acuminata have been analysed. Blood urea and mantle uric acid were significantly (P<0.005 and P<0.05 respectively) increased following injection with pleuroparietalpedal-visceral (PPPV Complex) ganglia homogenate within 2 hrs. On the contrary hepatopancreas urea and kidney uric acid levels were significantly (P<0.00) lowered. Cerebral ganglia homogenate and boiled extract of PPPV complex did not provoke any significant change in urea and uric acid levels. It is advocated that (a) neurohormone(s) which is (are) heat-labile and originate from the PPPV complex, influence(s) the nitrogen end-products in these snails.     

Responses of the neurosecretory cells of the freshwater snail,Indoplanorbis exustus to hydrothermal stress

Changes in the neurosecretory cell cytology of I. exustus subjected to hypertonic saline (0.1 ml of 1.5%/snail) loading and thermal stress (35°C) for two hours, have been investigated. Of the two types of neurosecretory cells A and B that are present in the central nervous system (CNS) of I. exustus, striking changes were evident only in B cells. After both treatments, there was about 33% decline in NSM (Neurosecretory material) intensity. However, the nuclear diameter of B cells was significantly (P < 0.001) increased in the snails administrated with hypertonic saline unlike in those exposed to 35°C wherein significant (P < 0.005) decline was evident. The adaptive significance of the neuroendocrine system of I exustus is discussed in relation to hydrothermal stress.     

Bihormonal control of oogenesis in the freshwater prawn, Macrobrachium kistnensis

The hormonal control of oogenesis has been investigated in the freshwater prawn, Macrobrachium kistnensis. Experiments using bilateral eyestalk ablation and injection of eyestalk extract supported the presence of a gonad inhibiting factor in the eyestalk of female prawns. Injections of brain and thoracic ganglion extract in normal female prawns and in those subjected to bilateral eyestalk ablation revealed the presence of a gonad stimulating factor in the central nervous tissue.     

Identification of an I-Ad restricted peptide on the 65-kilodalton heat shock protein of Mycobacterium avium

The 65 kilodalton heat shock protein (Hsp65) from mycobacterial species elicits immune responses and in some cases protective immunity. Here we have used a DNA sublibrary approach to identify antigenic fragments of Mycobacterium avium Hsp65 and a synthetic peptide approach to delineate CD4+ T cell determinants. A panel of Hsp65 reactive CD4+ T cell clones was established from lymph node cells obtained from BALB/c mice immunized with recombinant Hsp65. The clones were tested for proliferative reactivity against the products of the DNA sublibrary of the hsp65 gene. A T cell epitope, restricted by the I-Ad molecule, was identified within the C-terminal region of Hsp65 and the minimal epitope (amino acid residues 489-503) delineated using overlapping peptides spanning the C-terminal fragment. Additionally, the CD4+ T cell clone recognizing this epitope also responded to native Hsp65 present in M. avium lysates by both proliferation and cytokine production, indicating that the epitope was present and processed similarly both in the native and the recombinant forms of Hsp65. This sequence identified in BALB/c mice (Hsp65 489-503) is identical in other mycobacteria, notably M. tuberculosis, M. bovis and M. leprae, suggesting the epitope may have wider application in murine models of other mycobacterial infections.     

Hormonal control of osmoregulation in the indian freshwater leech,poecilobdella viridis (Blanchard)

Leeches maintained either in tap-water or under desiccated conditions show a continuous decline in body-weight. Debrained leeches show a significantly greater loss of weight than unoperated or sham-operated controls. Injections of brain homogenate (0.2 ml/leech = 3 brains/leech) significantly (p<0.01) reduces weight loss in debrained leeches, whereas saline injections are without effect. The results indicate that water (weight) loss is influenced by a neurosecretory hormone secreted by the brain of Poecilobdella viridis.

---