The experiments were made using serial samples from individuals and by injecting directly to their blood stream. Alloxan injeoted at near lethal doses caused substantial elevation of blood glucose in the adapted fish. However evidence against high insulin levels in the adapted fish imcluded: a) an improved response to a repeated glucose load, and b) an improved response to a single glucose load following pretreatment with insulin. Insulin (1 IU/Kg) was effective in reducing the high blood glucose post capture to low adapted levels. She space in which glucose is diluted following injection to the blood was estimated as 29.4 - 3.4% of the body weight and this space was significantly depleted of glucose by insulin infection. 3. The concentration of lactic acid formed in the lateral muscles during exercise or capture by trawl is related to the concentration of the glycogen stores of the muscle cells. The total store is normally between 200-400 mg lactate or glucose per 100 g muscle. The lactic acid levels of blood do not necessarily reflect the elevated muscle levels and a condition where the lactate is not released from the exhausted muscle tissue to the blood is described. Measurements of blood and lymph circulation in the muscle indicate that this release or non-release of lactate is independent of circulation. adrenergic stimulation promotes the expansion of muscle blood capillaries yet inhibits passage of lactate from muscle to blood. The evidence suggests that the non-release mechanism will be found in either a property of the Sarcolemma or in the chemical form of the lactic acid within the cell. The three phases; of blood glucose change and the release and non-release of lactic acid are discussed in relation to a general adaptation syndrome. Evidence for the existence in the fish of the stress apparatus is summarised and the time scale of the changes observed in the present study is compared with that recorded in other experiments examining change following stress in teleosts. During the study investigating release arid non-release of lactic acid a previously undescribed lymph circulation was discovered and these findings are described in part 2. The anatomy of the teleost lymph system is considered in relation to the observed flow of lymph. The vessels described by anatomists as longitudinal ventral, dorsal and lateral lymph ducts do not pass lymph to the head but act as collecting sinuses; the lymph flows from these sinuses to the neural lymph duct via the interspinal ducts. At the junction of each interspinal duct and the neural lymph duct there is a simple valve. lymph drains through this system as a result. ;of a negative pressure developed in the neural lymph canal by the respiratory movements Of the gill apparatus. The rigid nature of the neural lymph duct and the valves where the interspinal ducts join it allow the negative pressure to develop from a negative/ positive gill generated pressure cycle in the cephalic lymph sinuses. Valves linking cephalic lymph sinuses aid the return of lymph to the duct of Cuvier using the same pressure cycles. The drainage system is different in the salmonidae where the neural lymph duct is degenerate and the network of peripheral ducts serve as lymph return ducts. This can prohably be explained by the occurrence of higher circulation pressures in the salmonidae. Lymph from the neural lymph duct is a clear fluid having a composition similar to that of blood plasma. like blood, lymph clots contains normal blood levels of mobile leucocytes and thrombocytes and lymph reflects blood levels of lactate. 'Lymph contains nearly no erythrocytes and the protein concentration of neural duct lymph is 80.4% that of blood plasma, 131I iodinated human serum albumin (131I HSA) passes from the vascular space and appears in the neural lyijtph canal at 80/S plasma levels.51Or labelled erythrocytes are limited to the vascular space. The volume of blood in plaice muscle and skin is normally 0.07-0.1 M1 131 per 100 g muscle and 0.4-0.7 ml per 100 g skin. She I HSA labelled extra vascular space (interpreted as lymph) measured 4-7 ml per 100 g muscle and 60-74 ml per 100 g skin. She function and significance of the lymph system is discussed.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:593624 |
| Date | January 1972 |
| Creators | Wardle, Clement S. |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU387060 |
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