Antipyretic effect of centrally administered CRF

Acute central effects of corticotropin-releasing factor (CRF) on energy balance: Effects of age and gender

Previously demonstrated age-related changes in the catabolic melanocortin system that may contribute to middle-aged obesity and aging anorexia, raise the question of the potential involvement of corticotropin-releasing factor (CRF) in these phenomena, as this catabolic hypothalamic mediator acts downstream to melanocortins. Catabolic effects of CRF were shown to be mediated by both CRF1 (hypermetabolism) and CRF2 (anorexia) receptors. To test the potential role of CRF in age-related obesity and aging anorexia, we investigated acute central effects of the peptide on energy balance in male and female rats during the course of aging. Effects of an intracerebroventricular CRF injection on food intake (FI), oxygen-consumption (VO₂), core- and tail skin temperatures (Tc and Ts) were studied in male and female Wistar rats of five different age-groups (from 3- to 24-month). Anorexigenic responsiveness was tested during 180-min re-feeding (FeedScale) following 24-h fasting. Thermoregulatory analysis was performed by indirect calorimetry (Oxymax) complemented by thermocouples recording Tc and Ts (indicating heat loss). CRF suppressed FI in 3-month male and female animals. In males, CRF-induced anorexia declined with aging, whereas in females it was maintained in all groups. The peptide increased VO₂ and Tc in all male age-groups, while the weaker hypermetabolic response characterizing 3-month females declined rapidly with aging. Thus, age-related alterations in acute central anorexigenic and hypermetabolic effects of CRF show different non-parallel patterns in males and females. Our findings underline the importance of gender differences. They also call the attention to the differential age-related changes in the CRF1 and CRF2 receptor systems.

Central mediators involved in the febrile response: effects of antipyretic drugs

Fever is a complex signal of inflammatory and infectious diseases. It is generally initiated when peripherally produced endogenous pyrogens reach areas that surround the hypothalamus. These peripheral endogenous pyrogens are cytokines that are produced by leukocytes and other cells, the most known of which are interleukin-1β, tumor necrosis factor-α, and interleukin-6. Because of the capacity of these molecules to induce their own synthesis and the synthesis of other cytokines, they can also be synthesized in the central nervous system. However, these pyrogens are not the final mediators of the febrile response. These cytokines can induce the synthesis of cyclooxygenase-2, which produces prostaglandins. These prostanoids alter hypothalamic temperature control, leading to an increase in heat production, the conservation of heat, and ultimately fever. The effect of antipyretics is based on blocking prostaglandin synthesis. In this review, we discuss recent data on the importance of prostaglandins in the febrile response, and we show that some endogenous mediators can still induce the febrile response even when known antipyretics reduce the levels of prostaglandins in the central nervous system. These studies suggest that centrally produced mediators other than prostaglandins participate in the genesis of fever. Among the most studied central mediators of fever are corticotropin-releasing factor, endothelins, chemokines, endogenous opioids, and substance P, which are discussed herein. Additionally, recent evidence suggests that these different pathways of fever induction may be activated during different pathological conditions.

Central mediators involved in the febrile response: effects of antipyretic drugs

Fever is a complex signal of inflammatory and infectious diseases. It is generally initiated when peripherally produced endogenous pyrogens reach areas that surround the hypothalamus. These peripheral endogenous pyrogens are cytokines that are produced by leukocytes and other cells, the most known of which are interleukin-1β, tumor necrosis factor-α, and interleukin-6. Because of the capacity of these molecules to induce their own synthesis and the synthesis of other cytokines, they can also be synthesized in the central nervous system. However, these pyrogens are not the final mediators of the febrile response. These cytokines can induce the synthesis of cyclooxygenase-2, which produces prostaglandins. These prostanoids alter hypothalamic temperature control, leading to an increase in heat production, the conservation of heat, and ultimately fever. The effect of antipyretics is based on blocking prostaglandin synthesis. In this review, we discuss recent data on the importance of prostaglandins in the febrile response, and we show that some endogenous mediators can still induce the febrile response even when known antipyretics reduce the levels of prostaglandins in the central nervous system. These studies suggest that centrally produced mediators other than prostaglandins participate in the genesis of fever. Among the most studied central mediators of fever are corticotropin-releasing factor, endothelins, chemokines, endogenous opioids, and substance P, which are discussed herein. Additionally, recent evidence suggests that these different pathways of fever induction may be activated during different pathological conditions.

Involvement of endogenous corticotropin-releasing factor in mediation of neuroendocrine and behavioral effects to alpha-melanocyte-stimulating hormone

The present work was to study if the alpha-melanocyte-stimulating hormone (alpha-MSH) was involved in activation of the pituitary-adrenal axis (PAA) in rats. The hormone increased plasma corticosterone (CORT) level, and induced an anxiogenic response as indicated by results from the elevated plus-maze test. Intracerebroventricular administration of corticotropin-releasing factor (CRF) antiserum (1:10, 1:20 and 1:100 dilutions in 1microl volume), overcame both the anxiogenic response and the PAA activating effect induced by alpha-MSH (50 microg s.c.) in a concentration-dependent manner. CRF antibody at the doses applied did not modify either the elevated plus-maze responses or CORT level by itself. Our results reveal that both the anxiogenic and the PAA activating effects of alpha-MSH are mediated by CRF.

Cytokines and fever. Mechanisms and sites of action

The cytokines interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF)-alpha induce increases in body temperature via direct and indirect actions on the brain and are believed to act as endogenous pyrogens. We studied the mechanisms of action of these cytokines on fever in rats. Local administration of lipopolysaccharide (LPS) into a subcutaneous air pouch elicits marked fever, accompanied by increases in the levels of TNF-alpha, IL-1, and IL-6 in the pouch, but only IL-6 in the plasma. Thus, TNF-alpha and IL-1 probably act locally to stimulate the release of a secondary circulating mediator(s) (e.g., IL-6) that can interact with the brain. Neural afferents have also been implicated in relaying messages to the brain. Pyrogenic responses are reportedly attenuated by subdi-aphragmatic vagotomy; however, we failed to observe inhibition of fever in vagotomized rats injected with either LPS or a pyrogenic dose of IL-1, although behavioral responses are abolished.

Role of interleukin-1 in stress responses. A putative neurotransmitter

Recently, the central roles of interleukin-1 (IL-1) in physical stress responses have been attracting attention. Stress responses have been characterized as central neurohormonal changes, as well as behavioral and physiological changes. Administration of IL-1 has been shown to induce effects comparable to stress-induced changes. IL-1 acts on the brain, especially the hypothalamus, to enhance release of monoamines, such as norepinephrine, dopamine, and serotonin, as well as secretion of corticotropin-releasing hormone (CRH). IL-1-induced activation of the hypothalamo-pituitary-adrenal (HPA) axis in vivo depends on secretion of CRH, an intact pituitary, and the ventral noradrenergic bundle that innervates the CRH-containing neurons in the paraventricular nucleus of the hypothalamus. Recent studies have shown that IL-1 is present within neurons in the brain, suggesting that IL-1 functions in neuronal transmission. We showed that IL-1 in the brain is involved in the stress response, and that stress-induced activation of monoamine release and the HPA axis were inhibited by IL-1 receptor antagonist (IL-1Ra) administration directly into the rat hypothalamus. IL-1Ra has been known to exert a blocking effect on IL-1 by competitively inhibiting the binding of IL-1 to IL-1 receptors. In the latter part of this review, we will attempt to describe the relationship between central nervous system diseases, including psychological disorders, and the functions of IL-1 as a putative neurotransmitter.

Corticotropin-releasing factor receptors: physiology, pharmacology, biochemistry and role in central nervous system and immune disorders

Corticotropin-releasing factor (CRF) plays a major role in coordinating the endocrine, autonomic, behavioral and immune responses to stress through actions in the brain and the periphery. CRF receptors identified in brain, pituitary and spleen have comparable kinetic and pharmacological characteristics, guanine nucleotide sensitivity and adenylate cyclase-stimulating activity. Differences were observed in the molecular mass of the CRF receptor complex between the brain (58,000 Da) and the pituitary and spleen (75,000 Da), which appeared to be due to differential glycosylation of the receptor proteins. The recently cloned CRF receptor in the pituitary and the brain (designated as CRF1) encodes a 415 amino acid protein comprising seven putative membrane-spanning domains and is structurally related to the calcitonin/vasoactive intestinal peptide/growth hormone-releasing hormone subfamily of G-protein-coupled receptors. A second member of the CRF receptor family encoding a 411 amino acid rat brain protein with approximately 70% homology to CRF1 has recently been identified (designated as CRF2); there exists an additional splice variant of the CRF2 receptor with a different N-terminal domain encoding a protein of 431 amino acids. In autoradiographic studies, CRF receptors were localized in highest densities in the anterior and intermediate lobes of the pituitary gland, olfactory bulb, cerebral cortex, amygdala, cerebellum and the macrophage-enriched zones and red pulp regions of the spleen. CRF can modulate the number of CRF receptors in a reciprocal manner. For example, stress and adrenalectomy increase hypothalamic CRF secretion which, in turn, down-regulates CRF receptors in the anterior pituitary. CRF receptors in the brain and pituitary are also altered as a consequence of the development and aging processes. In addition to a physiological role for CRF in integrating the responses of the brain, endocrine and immune systems to physiological, psychological and immunological stimuli, recent clinical data implicate CRF in the etiology and pathophysiology of various endocrine, psychiatric, neurologic and inflammatory illnesses. Hypersecretion of CRF in the brain may contribute to the symptomatology seen in neuropsychiatric disorders, such as depression, anxiety-related disorders and anorexia nervosa. Furthermore, overproduction of CRF at peripheral inflammatory sites, such as synovial joints may contribute to autoimmune diseases such as rheumatoid arthritis. In contrast, deficits in brain CRF are apparent in neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease and Huntington's disease, as they relate to dysfunction of CRF neurons in the brain areas affected in the particular disorder. Strategies directed at developing CRF-related agents may hold promise for novel therapies for the treatment of these various disorders.

What roles does the organum vasculosum laminae terminalis play in fever in rabbits?

Experiments were designed to clarify the role of the brain's organum vasculosum laminae terminalis (OVLT) in the development of fever in rabbits. Rectal and ear skin temperatures were recorded in conscious animals in which the OVLT had been electrolytically destroyed or in which the preoptic anterior hypothalamus (PO/AH) had been transected bilaterally. When the OVLT had been ablated the febrile responses to intravenous injection of interleukin-1 beta (IL-1 beta) or tumour necrosis factor alpha were significantly attenuated, while those to intracerebroventricular injection of IL-1 beta were not affected. Fever induced by intracerebroventricular injection of prostaglandin E2 (PGE2) was prolonged significantly. The febrile responses to intravenous injection of IL-1 beta and to intracerebroventricular injection of PGE2 were attenuated when the transection was located caudally to the anterior wall of the third ventricle and extended laterally more than about 3 mm in the ventricular wall. The results show that the OVLT region is a site through which signals to increase body temperature are transferred from the blood to the brain in rabbits.

Does endogenous peripheral arginine vasopressin have a role in the febrile responses of conscious rabbits?

1. The actions of peripheral arginine vasopressin (AVP) on the febrile responses of conscious rabbits induced by peripherally administered polyinosinic:polycytidylic acid (poly(I).poly(C)) have been studied using an AVP V1 receptor antagonist ([deamino-Pen1, O-Me-Tyr2, Arg8]-vasopressin). 2. Temperature responses were monitored continuously using rectal thermistor probes. Test substances were administered intravenously (i.v.). Blood samples were taken at timed intervals from a marginal ear vein and plasma PGE2 and PGF2 alpha levels determined by radioimmunoassay. 3. Poly(I).poly(C) (2.5 micrograms/kg) stimulated a reproducible biphasic rise in body temperature with a lag phase of 45-60 min and peaks at 90 and 225 min. The febrile response was accompanied by a 5-fold rise in circulating immunoreactive (ir) PGE2, which peaked after 90 min and remained elevated up to 300 min. Poly(I).poly(C) also stimulated a 2.5-fold rise in circulating irPGF2 alpha, which peaked after 150 min and was followed by a return to basal levels after 300 min. 4. The overall magnitude of the febrile response to poly(I).poly(C) (2.5 micrograms/kg, i.v.) was significantly antagonized by the AVP V1 receptor antagonist (250 micrograms/kg, i.v.) administered 5 min prior to the pyrogen. 5. The irPGE2 response to poly(I).poly(C) (2.5 micrograms/kg, i.v.) was significantly antagonized by the AVP V1 receptor antagonist (250 micrograms/kg, i.v.) administered 5 min prior to the pyrogen. The irPGF2 alpha response was only reduced at the peak 150 min time point measurement. 6. In conclusion, these results show a modulatory role for a peripherally administered AVP V1 antagonist in the febrile responses to poly(I).poly(C), suggesting a possible propyretic role for endogenous peripheral AVP. This modulatory role appears to be mediated via actions on prostaglandin E2.

Fever: causes and consequences

The present review distinguishes pathogenic, neurogenic, and psychogenic fever, but focuses largely on pathogenic fever, the hallmark of infectious disease. The data presented show that a complex cascade of events underlies pathogenic fever, which in broad outline - and with frank disregard of contradictory data - can be described as follows. An invading microorganism releases endotoxin that stimulates macrophages to synthesize a variety of pyrogenic compounds called cytokines. Carried in blood, these cytokines reach the perivascular spaces of the organum vasculosum laminae terminalis (OVLT) and other regions near the brain where they promote the synthesis and release of prostaglandin (PGE2). This prostaglandin then penetrates the blood-brain barrier to evoke the autonomic and behavioral responses characteristic of fever. But then once expressed, fever does not continue unchecked; endogenous antipyretics likely act on the septum to limit the rise in body temperature. The present review also examines fever-resistance in neonates, the blunting of fever in the aged, and the behaviorally induced rise in body temperature following infection in ectotherms. And finally it takes up the question of whether fever enhances immune responsiveness, and through such enhancement contributes to host survival.

A possible role for endogenous peripheral corticotrophin-releasing factor-41 in the febrile response of conscious rabbits

1. The actions of peripheral corticotrophin-releasing factor-41 (CRF-41) on the febrile responses of conscious rabbits induced by peripherally administered polyinosinic.polycytidylic acid (poly(I).poly(C)) have been studied using a CRF-41 receptor antagonist (alpha-helical CRF(9-41) and anti-CRF-41 monoclonal antibodies. 2. Temperature responses were monitored continuously using rectal thermistor probes. Test substances were administered intravenously (i.v.), or for central CRF-41 antagonism experiments, via an indwelling third ventricle cannula (I.C.V.). Blood samples were taken at time intervals from a marginal ear vein and plasma cortisol levels determined by radioimmunoassay. 3. Poly(I).poly(C) (2.5 micrograms/kg) stimulated a reproducible biphasic rise in body temperature with a lag phase of 45-60 min and peaks at 90 and 225 min. 4. The febrile response to poly(I).poly(C) (2.5 micrograms/kg I.V.) was antagonized by blockade of peripheral CRF-41 actions using either monoclonal anti-CRF-41 antibodies (2.5 mg/kg i.v.) or the CRF-41 receptor antagonist (alpha-helical CRF(9-41); 25 micrograms/kg i.v.) administered 5 min prior to the pyrogen. 5. Centrally administered CRF-41 receptor antagonist (2.5 micrograms/kg I.C.V.) failed to affect the febrile response to poly(I).poly(C) (2.5 micrograms/kg i.v.). 6. CRF-41 immunoneutralization after the onset of temperature rises caused an immediate and significant defervescence. 7. In conclusion, these results suggest a modulatory pro-pyretic role for endogenous peripheral CRF-41 in the febrile responses to poly(I).poly(C).

Functions and mechanisms of interleukin 1 in the brain

Interleukin 1 (IL-1), a cytokine with diverse actions, has been proposed as a mediator of both beneficial and detrimental responses to inflammation and injury. Many of the actions of IL-1, such as those on behaviour, neuroendocrine function, sleep, fever and metabolism, are mediated by the CNS, as described here by Nancy Rothwell. IL-1 can be synthesized and act locally within the brain to influence neuronal and glial function, and has been strongly implicated in normal brain development and responses to brain injury. A number of distinct sites and mechanisms of action have been proposed to explain these diverse effects of IL-1 in the brain, probably involving multiple receptor subtypes and complex interactions with neurotransmitters and neuropeptides.

Central effects of CRF on metabolism and energy balance

CRF is recognised for its actions on pituitary ACTH release, but also has direct effects within the brain which are important in mediating physiological responses to stress. Behavioral effects of CRF include increased locomotor activity and inhibition of food intake and its actions on metabolism are mediated mainly by activation of the sympathetic nervous system. CRF appears to be important in the regulation of energy balance and body weight, influencing both food intake and sympathetically-mediated thermogenesis. A defect in the synthesis or release of CRF has been implicated in the development of obesity in laboratory animals, since the condition is alleviated by adrenalectomy, hypophysectomy or exogenous CRF treatment. Recent data have revealed an additional role for CRF as a mediator of the neuroendocrine and metabolic responses to immune signals, particularly cytokines. The central actions of CRF are independent of the pituitary but may involve release of proopiomelanocortin products within the brain. CRF is thus emerging as an important integrator of the physiological responses to stress, infection and immunity, a finding which may have important implications for future therapies.

Criteria for establishing a physiological role for brain peptides. A case in point: the role of vasopressin in thermoregulation during fever and antipyresis

This paper has attempted to present and discuss the criteria necessary for the evaluation of a specific physiological role for a peptide in the CNS. These criteria are based on many experimental approaches to the problem and conclusions must be supported by the weight of the evidence. These criteria were illustrated by examining the hypothesis that AVP is an antipyretic neurotransmitter involved in regulating febrile increases in Tb by release and action in the VSA of the brain. The weight of the evidence in this case implies that this hypothesis is essentially correct. The only serious conflicting evidence comes from the work with Brattleboro rats. It is hoped that further research will resolve these discrepancies or result in a suitably modified hypothesis.

Alterations in local cerebral glucose utilization following central administration of corticotropin-releasing factor in rats

We have examined the effects of intracerebroventricular administration of corticotropin-releasing factor (CRF) (5.25 nmol in 10 microliters of saline) on glucose utilization, an index of cerebral function, in 65 anatomically discrete regions of rat brain by using the 14C-2-deoxyglucose quantitative autoradiographic technique. CRF administration increased plasma glucose concentrations with a temporal onset and magnitude of response similar to those previously reported. CRF differentially affected glucose utilization (GU) in discrete regions of rat brain. Consonant with the hypophysiotropic role for CRF, pronounced increases in GU were seen in median eminence and lateral nucleus of the hypothalamus. CRF also increased GU in brain regions implicated in mediating responses to stress including locus coeruleus and median raphe nucleus. In contrast, reductions in GU were observed in prefrontal cortex and nucleus accumbens. Punctate increases in GU were noted in the cerebellar cortex. Furthermore, large increases in GU occurred in vermis, inferior olive, and red nucleus substantiating a neurotransmitter role for CRF in the olivocerebellar pathway. Additional brain areas showing significant alterations in GU in response to CRF included anteroventral, anterior pretectal, and posterolateral nuclei of the thalamus, fornix, dorsal tegmental nucleus, spinal trigeminal nucleus, and cuneate nucleus. These data demonstrating regional changes in GU in response to CRF administration further elucidate the neuroanatomical substrates underlying the actions of CRF in brain and support the role of this neuropeptide in coordinating responses to stress.

Changes in body temperature after administration of antipyretics, LSD, delta 9-THC and related agents: II

Antipyretics, in particular acetaminophen, aspirin and ibuprofen, constitute the single most important class of drugs used therapeutically for an effect on body temperature. Hallucinogens exert prominent actions on the central nervous system, and it is not surprising that, like so many other centrally-acting agents, they too often affect temperature. This compilation primarily covers the considerable amount of data published from 1981 through 1985 on the interactions of these drugs and thermoregulation, but data from many earlier papers not included in a previous compilation are also tabulated. The effects of agents not classically considered as antipyretics on temperatures of febrile subjects are also covered. The information listed includes the species used, the route of administration and dose of drug, the environmental temperature at which experiments were performed, the number of tests, the direction and magnitude of change in body temperature and remarks on special conditions, such as age or brain lesions. Also indicated is the influence of other drugs, such as antagonists, on the response to the primary agent.

The antagonistic effect of corticotropin-releasing factor on pentobarbital in rats

The effects of corticotropin-releasing factor (CRF) on pentobarbital-induced sleeping time and hypothermia in rats were studied. Intraventricular administration of CRF significantly shortened the sleeping time induced by pentobarbital injection (50 mg/kg b.wt.) in a dose-dependent manner. CRF also attenuated the hypothermic effect of pentobarbital. However, peripheral administration of CRF did not affect the action of pentobarbital. alpha-Helical CRF9-41, CRF antagonist, reversed the effects of CRF. These results suggest that CRF antagonizes the effects of pentobarbital within the central nervous system.

Central nervous system effects of peptides, 1980-1985: a cross-listing of peptides and their central actions from the first six years of the journal Peptides

A tabular synopsis is presented for articles concerned with the effects of peptides on the central nervous system that appeared in the journal Peptides from 1980-1985. A table arranged alphabetically by peptide and one arranged by effects, both listing routes of injection, species, direction of change, and qualifying notes, provides easy cross-referencing of peptides and their effects. Over 80 peptides and over 135 effects are listed. The list of peptides includes, but is not limited to: ACTH, angiotensin, bombesin, bradykinin, calcitonin, casomorphin, CCK, ceruletide, CGRP, CRF, dermorphin, DSIP, dynorphin, endorphins, enkephalins, GRF, gastrin, LHRH, litorin, metkephamid, MIF-l, motilin, MSH, NPY, NT, oxytocin, ranatensin, sauvagine, substances P and K, somatostatin, TRH, VIP, vasopressin, and vasotocin. The list of effects includes, but is not limited to: aggression, alcohol, analgesia, attention, avoidance, behavior, cardiovascular regulation, catalepsy, conditioned behavior, convulsions, dopamine binding and metabolism, discrimination, drinking, EEG, exploration, feeding, fever, gastric secretion, GI motility, grooming, learning, locomotor behavior, mating, memory, neuronal activity, open field, operant behavior, rearing, respiration, satiety, scratching, seizure, sleep, stereotypy, temperature, thermoregulation and tolerance.

Corticotropin-releasing factor receptors in the pituitary gland and central nervous system: methods and overview

Studies with the radioiodinated oCRF analog, Nle21, 125I-Tyr32-oCRF have identified, characterized, and localized high affinity binding sites for CRF in anterior and intermediate lobes of rat pituitary, in anterior lobe of human pituitary, and in rat, monkey, and human brain. The pharmacology and distribution of Nle21, 125I-Tyr32-oCRF binding in the pituitary gland correlate well with the biological potency and sites of action of CRF and suggest that these CRF binding sites represent specific receptors that mediate the well-established actions of CRF on the anterior pituitary and on the intermediate lobe of the pituitary. The studies in adrenalectomized rats demonstrating that endogenous CRF is capable of modulating its receptor density provide additional evidence that the radioligand labels the functional CRF receptor. The areas of distribution of Nle21, 125I-Tyr32-oCRF binding sites in the rat CNS correlate well with the immunohistochemical distribution of CRF pathways and the pharmacological sites of action of CRF. These data confirm the established role of CRF in regulating secretion of POMC-derived peptides from the pituitary gland. In addition, the data support a physiological role for endogenous CRF in regulating CNS activity and suggest the importance of this neuropeptide in integrating endocrine and visceral functions and behavior, especially in response to stress. Studies to characterize CRF receptors and CRF-containing pathways in the brain provide a means for better understanding the various functions of this neuropeptide in different areas of the CNS. Finally, the ability to map CRF receptors in postmortem human tissue provides a basis for studying the role of CRF in a variety of endocrine, neurological, and psychiatric disorders.

Administered peptides inhibit the degradation of endogenous peptides. The dilemma of distinguishing direct from indirect effects

Virtually all peptides are biologically active following central administration as a consequence of both direct and indirect cellular actions. Direct effects are mainly interactions with specific membrane receptors but may include unions with other components of the receptor/effector complex. Significant indirect biological effects of exogenous peptides, including apparent secretagogue effects on endogenous peptides largely overlooked in practice, result from extensive competition with endogenous peptides for degradative enzymes (peptidases). A consequence of this competition is enhancement of tonic or intermittent activity of endogenous peptides. The pharmacological profile of any peptide reflects or includes, therefore, the spectrum of endogenous peptides that is protected from peptidase action. It is likely that certain pharmacologically active peptides, including a large number of di-, tri- and oligo-peptides, elicit responses mainly or exclusively by competing for peptidases. Therefore, reliable estimates of the relative contributions of direct and indirect actions of exogenous peptides may be difficult, if not impossible, to obtain.

Changes in body temperature after administration of amino acids, peptides, dopamine, neuroleptics and related agents: II

This survey begins a second series of compilations of data regarding changes in body temperature induced by drugs and related agents. The information listed includes the species used, the route of administration and dose of drug, the environmental temperature at which experiments were performed, the number of tests, the direction and magnitude of change in body temperature and remarks on the presence of special conditions, such as age or brain lesions. Also indicated is the influence of other drugs, such as antagonists, on the response to the primary agent. Most of the papers were published since 1978, but data from many earlier papers are also tabulated.