Related Experiment Videos
Lethal effect of male rat submandibular gland homogenate for rat neonates
Insights
Suckling rats injected with male submandibular gland homogenate (SMGH) died due to absorbed trypsin-like enzymes. Adult rats tolerated SMGH, suggesting age-dependent enzyme inactivation is critical for survival.
Area of Science:
- Toxicology
- Biochemistry
- Developmental Biology
Background:
- The submandibular gland (SMG) produces various bioactive compounds, including enzymes.
- The physiological impact of SMG homogenate, particularly in developing organisms, is not fully understood.
Purpose of the Study:
- To investigate the toxicity of male submandibular gland homogenate (SMGH) in rats of different ages.
- To determine the role of age-dependent factors in the response to SMGH exposure.
Main Methods:
- Subcutaneous injection of male SMGH and liver homogenate (LH) into suckling, weanling, and adult rats.
- Monitoring survival rates within 24 hours post-injection.
- Quantifying serum trypsin-like activity in injected rats.
Main Results:
- Suckling rats injected with SMGH exhibited high mortality within 24 hours, unlike those receiving LH or older rats receiving SMGH.
- A significant increase (1200%) in serum trypsin-like activity was observed in surviving suckling rats after SMGH injection.
- Adult rats showed a much smaller increase (46%) in serum trypsin-like activity following a proportionally similar SMGH dose.
Conclusions:
- Suckling rats are highly susceptible to the toxic effects of male SMGH, likely due to impaired enzyme inactivation.
- The observed mortality in pups is attributed to the absorption of active trypsin-like enzymes leading to a hypotensive crisis.
- Age-dependent differences in enzyme metabolism play a crucial role in determining the toxicity of SMGH.
Abstract:
Suckling rats injected subcutaneously with male submandibular gland homogenate (SMGH), but not liver homogenate (LH), died within 24 h. Weanling and adult rats injected with proportionately greater doses of male SMGH did not die. Suckling rats injected with male SMGH exhibited a 1200% increase in serum trypsin-like activity while the corresponding increase for an adult receiving a proportionately similar dose was 46%. We suggest that pups injected subcutaneously with SMGH absorbed trypsin-like enzymes into their bloodstream, were unable to inactivate the enzymes, and suffered a hypotensive crisis leading to death.