Guinea-pigs

Guinea pig platelets contain circumfiential microtubules, dense bodies, alpha granules, glycogen particles and an open canalicular system. Ultrastmctural features of guinea pig platelets are similar to that of human platelets. 

Platelet glass retention indices for Guinea pig platelets is similar to that for human platelets. 

Guinea pig platelets aggregate readily in response to ADP and consistently have a biphasic 

Avian thrombocytes aggregate poorly in response to ADP, collagen, arachidonic acid, and thrombin. 

With few exceptions, platelets of all species have similar ultrastmctural features and contain similar metabolic pathways. Therefore, species-dependent differences in platelet function tend to be quantitative rather than quantitative. Platelets from larger ruminants, including cattle, sheep, and goats, do not contain an open canalicular system and appear to be less functional than platelets from other species. Platelet function may be less irrqrortant to these species because they are not frequently exposed to trauma in the wild. Alternatively, carnivores are regularly exposed to trauma in the process of hunting and defending themselves. These species tend to have highly functional platelets and also can enhance platelet function at times of excitement or fear as a result of epinephrine release. 

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Propargyl alcohol is a primary skin irritant and a severe eye irritant and is toxic by all means of ingestion all necessary precautions must be taken to avoid contact with Hquid or vapors. The LD q is 0.07 mL/kg for white rats and 0.06 mL/kg for guinea pigs. 

Health nd Safety Factors. Butenediol is noncorrosive and stable under normal handling conditions. It is a primary skin irritant but not a sensitizer contact with skin and eyes should be avoided. It is much less toxic than butynediol. The LD q is 1.25 mL/kg for white rats and 1.25—1.5 mL/kg for guinea pigs. 

Health and Safety Factors. Butyrolactone is neither a skin irritant nor a sensiti2er however, it is judged to be a severe eye irritant in white rabbits. The acute oral LD q is 1.5 ml,/kg for white rats or guinea pigs. Subacute oral feeding studies were carried out with rats and with dogs. At levels up... 

The cured 2-cyanoacryhc ester polymers are relatively nontoxic. Oral doses of 6400 mg/kg failed to kill laboratory rats. Mild skin irritation was observed with guinea pigs, but there was no evidence of sensitization or absorption through the skin (15). 

Toxicity. The lethal dose of Mgp2 to guinea pigs by ingestion is 1000 mg/kg (17). 

Toxicology and Handling. The lethal dose by ingestion in guinea pigs is 150 mg/kg body weight (13). The TLV for KHF2 is 2.5 mg /m ... 

Oral LD q levels have been deterrnined in the mouse at 470 mg/kg (21) and the guinea pig at 7750 mg/kg (22). Several other studies (23—25) have shown that large quantities of both synthetic and natural glycerol can be adniinistered orally to experimental animals and humans without the appearance of adverse effects. Intravenous adniinistration of solutions containing 5% glycerol to animals and humans has been found to cause no toxic or otherwise undesirable effects (26). 

The smallest sequence possessing most of the neurotensin spectmm of activities and its high potency is the hexapeptide C-terminus (1). [D-Trp ]-Neurotensin acts like a neurotensin antagonist in perfused heart preparations, but acts like a full agonist in guinea pig atria and rat stomach strips (122). 

The LC q (lowest possible lethal concentration) has been reported to be 23 ppm for a 30 min exposure time (mouse), 53 ppm for an exposure time of 100 min (rat, rabbit, and guinea pig), and 200 ppm for an exposure time of 10 min (monkey). No toxic effects were reported upon exposure to 1 ppm for 7 h/d over 55 days. The oral LD q (rat) of ketene is 1300 mg/kg, the low level of toxicity probably being due to the almost immediate formation of acetic acid and other acetates in the digestive tract. 

Long-lasting vasoconstriction is produced by the ETs in almost all arteries and veins and several studies have shown that ET-1 causes a reduction in renal blood flow and urinary sodium excretion. ET-1 has been reported to be a potent mitogen in fibroblasts and aortic smooth muscle cells and to cause contraction of rat stomach strips, rat colon and guinea pig ileum. In the central nervous system, ETs have been shown to modulate neurotransmitter release. 

Because iCg values for competitive antagonists represent tme dissociation constants, these make possible quantitative interpretations of SARs. Significant use also has been made of iCg values in the quantitative comparison of receptors to determine whether receptors that respond to the same agonists are identical or whether responses produced by different agonists are initiated at the same receptors (44,46). Thus, beta-adrenoceptors in human and guinea pig preparations can be direcdy compared and selective and antagonists quantitated (Table 3). 

Whereas the agreement between the values in humans and guinea pig is close, this is not always so. For example, in human and rodent 5-HT p receptors, significant pharmacological differences are conferred by a single amino acid residue. 

The Hquid reacts violentiy with water, releasing HCl and other gases ia sufficient amounts to cause sudden mpture of closed or inadequately vented containers. The acid reaction products can react with metals to generate hydrogen, which is flammable and explosive. The oral LD q in rats is 380 mg/kg the inhalation LC q for rats is 48 ppm/4 h, and for guinea pigs, 53 ppm/4 h (35). 

Chronic Toxicity. The effects of repeated oral exposure to phthalates for periods ranging from a few days to 2 years have been studied in a number of animal species including rats, mice, hamsters, guinea pigs, ferrets, and dogs (37). 

Skin contact can result in irritation, bUstering, or bums if confined to the skin by clothing or shoes, but is not injurious if it evaporates readily. Liquid propylene oxide exposure to the eyes causes injury in rabbits. Ingestion of aqueous solutions of 5 and 10% propylene oxide showed LD q values of 1.14 g/kg for rats and 0.69 g/kg for guinea pigs (253). 

Health and Safety Factors. Results of acute oral toxicity studies of 2-pyrrohdinone on white rats and guinea pigs show the LD q to be 6.5 ml,/kg. Skin patch tests on 200 human subjects indicate that 2-pyrrohdinone is a skin kritant, but there is no indication of sensitising action. It is a mild eye irritant (79). 

The dermal adsorption of DEBT in humans has been studied in the Netherlands by appHcation of DEBT as undiluted technical material or as 15% solutions in alcohol. Labeled material was recovered from the skin, and absorption of DEBT was indicated by the appearance of label in urine after two hours of skin exposure. About 5—8% of the appHed treatments was recovered as metaboHtes from urine, and excretion of metaboHtes in the urine came to an end four hours after exposure ended. DEBT did not accumulate in the skin, and only a small (less than 0.08%) amount ended up in feces. Curiously, less has been absorbed through skin from 100% DEBT appHcation (3—8%, mean of 5.6%) than from 15% alcohol appHcation (4—14%, mean of 8.4%). These results have been described as consistent with previous absorption/metaboHsm studies using guinea pigs, rats, and hairless dogs. Other pubHcations on DEBT toxicology have been cited (92). 

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