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Effects of intravenous epinephrine on macaque platelets
Abstract:
Blood was obtained from three species of macaques for a study of platelets. A rapidly mobilizable platelet pool was demonstrated in rhesus macaques given intravenous epinephrine. The number of platelets/ml of blood increased about 30% 3 to 5 min after epinephrine was given. The size distributions of the platelets were similar before and after injection. Platelet aggregability was increased after injection. Basal platelet aggregabilities, as measured by platelet aggregate ratios, were similar in rhesus macaques. Celebes black macaques, and human subjects, but were significantly greater in cynomolgus macaques than in the other three species.
Insights
Rhesus macaques have a rapidly mobilizable platelet pool, with platelet counts increasing 30% after epinephrine injection. Cynomolgus macaques showed higher basal platelet aggregability than other species and humans.
Area of Science:
- Hematology
- Primate research
- Platelet physiology
Background:
- Platelets play a crucial role in hemostasis and thrombosis.
- Understanding platelet dynamics in different species is important for comparative physiology and biomedical research.
Purpose of the Study:
- To investigate the presence of a rapidly mobilizable platelet pool in macaques.
- To compare basal platelet aggregability across different macaque species and humans.
Main Methods:
- Blood samples were collected from rhesus, Celebes black, and cynomolgus macaques.
- Intravenous epinephrine was administered to rhesus macaques to assess platelet response.
- Platelet counts, size distributions, and aggregability (platelet aggregate ratios) were measured.
Main Results:
- A rapidly mobilizable platelet pool was demonstrated in rhesus macaques, with a ~30% increase in platelet count 3-5 minutes post-epinephrine.
- Platelet size distributions remained consistent before and after epinephrine administration.
- Basal platelet aggregability was similar in rhesus macaques, Celebes black macaques, and humans.
- Cynomolgus macaques exhibited significantly higher basal platelet aggregability compared to the other three groups.
Conclusions:
- Rhesus macaques possess a readily available pool of platelets that can be mobilized by epinephrine.
- Platelet aggregability varies significantly among macaque species, with cynomolgus macaques showing heightened responsiveness.
- These findings contribute to understanding species-specific platelet physiology and potential implications for thrombotic risk.
