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PubMed1975

Brain free fatty levels in rats sacrificed by decapitation versus focused microwave irradiation.

Values are presented for whole brain free fatty acid levels of rats sacrificed by decapitation vs focused microwave irradiation. Free fatty acids were quantitated by specific colorimetric analysis. Within ca. 1 min of sacrifice by either decapitation or microwave, rat whole brain free fatty acid concentrations ranged from ca. 80-100 mug/g fresh tissue. If the brain remained in the head for a total of 5 min after decapitation, free fatty acid levels increased by over 100%. The free fatty acids at this time were enriched with arachidonic acid. The increase in free fatty acid levels following decapitation was completely absent in rats sacrificed by the microwave irradiation. This microwave technique could be a valuable tool in determining free fatty acid and other heat stable compounds in brain tissue.

Animals↗
PubMed1992

Decapitation ischemia-induced release of free fatty acids in mouse brain. Relationship with diacylglycerols and lysophospholipids.

In this study, the release of lysophospholipids (to depict phospholipase A2 activity) and diacylglycerols (DG) (to depict stimulated hydrolysis of polyphosphoinositides) was related to the decapitation-induced release of free fatty acid (FFA) in the mouse brain. To assay for lysophospholipids, Balb/c mice were injected intracerebrally with either [3H]choline or [3H]inositol for 16 h in order to label their respective phospholipids. These lipids were examined at various times (30 s to 30.5 min) after decapitation. Between 30 s and 1.5 min after decapitation, the rate of FFA release (3 micrograms FA/mg FA in phospholipids/min) was three times more rapid than that between 10 and 15 min (0.8 microgram FA/mg FA in phospholipids/min). FFA released during the initial phase were enriched in 20:4 and 18:0 whereas those released during the latter phase were nonspecific. The DG fatty acids are enriched in 18:0 and 20:4. Ischemia induced a rapid release of DG as measured by its fatty acid content (3.2 micrograms FA/mg FA in phospholipids/min). Unlike FFA, the level of DG reached a plateau after 1.5 min and remained elevated for the entire 30.5 min. In agreement with previous notions indicating the involvement of phospholipase A2 in ischemic insult, steady increases in radioactivity of both lysophosphatidylcholines and lysophosphatidylinositols were observed with time after decapitation. Based on the preferential increase in both 18:0 and 20:4 during the initial time period, the results suggest that poly-PI hydrolysis coupled to DG-lipase may contribute to the initial release of FFA, whereas the FFA released subsequent to the initial phase may be mainly a result of activation of phospholipase A2 acting on phosphatidylcholines and phosphatidylinositols.

Animals↗
PubMed1988

Neocortical and hippocampal electrical activity following decapitation in the rat.

It has been debated whether or not decapitation of conscious animals is a humane procedure. This problem may be clarified on the basis of recent research that has indicated that neocortical low voltage fast activity (LVFA) and hippocampal rhythmical slow activity (RSA) can result from activity in either the cholinergic corticipetal projections from the basal forebrain or the serotonergic corticipetal projections from the brainstem. These inputs appear to produce, respectively, atropine-sensitive LVFA and RSA and atropine-resistant LVFA and RSA. In waking animals, atropine-resistant LVFA and RSA occur only in close correlation with motor activities such as spontaneous changes in posture, walking or struggling (Type 1 behavior). Painful stimuli readily elicit both Type 1 behavior and LVFA and RSA in atropine-treated rats. Atropine-sensitive LVFA and RSA may occur in anesthetized as well as in conscious animals, but atropine-resistant LVFA and RSA are generally absent during anesthesia. In the experiments reported here, rats were decapitated: (1) in the normal waking state; (2) after pretreatment with atropine or scopolamine; or (3) following induction of anesthesia with ethyl ether. Clear hippocampal RSA and neocortical LVFA were observed in conditions 1 and 3 but not in condition 2. It is concluded: (A) that atropine-sensitive LVFA and RSA are not good indices of conscious perception of pain since these waveforms occur during anesthesia as well as in the waking state; and (B) that the cerebral reaction to decapitation does not resemble the usual cerebral reaction to painful stimuli. This is consistent with the view that decapitation is not inhumane.

Animals↗
PubMed1988

Inhibition of post-decapitation convulsions in the rat by dibenzothiepin neuroleptics via alpha 1-adrenoceptor blockade.

The mechanisms involved in inhibitory effects of isofloxythepin, a newly synthesized dibenzothiepin neuroleptic, on post-decapitation convulsions were studied in rats. Isofloxythepin (0.05-2.0 mg/kg s.c.) inhibited post-decapitation convulsions in a dose-dependent manner as shown by the decrease in the incidence and the shortening of the duration of convulsions. The convulsions were also inhibited by oxyprothepin, zotepine or chlorpromazine but not by haloperidol. Prazosin and bunazosin, both alpha 1-adrenoceptor antagonists, suppressed the post-decapitation convulsions but a non-selective alpha 2-adrenoceptor agonist, tolazoline, was without effect. The convulsions were inhibited dose dependently by clonidine, an alpha 2-adrenoceptor agonist, but were prolonged in duration by yohimbine, an alpha 2-adrenoceptor antagonist. Yohimbine antagonized the inhibitory effects of isofloxythepin, prazosin and clonidine. The noradrenaline-induced contraction of rat vas deferens was inhibited by isofloxythepin, prazosin or chlorpromazine. Isofloxythepin bound to alpha 1-receptors as did chlorpromazine in the rat brain cortex. The results imply that post-decapitation convulsions seem to be inhibited by a block of postsynaptic alpha 1-adrenoceptors, enhanced by a block of presynaptic alpha 2-adrenoceptors and reduced by isofloxythepin via the blocking of postsynaptic alpha 1-adrenoceptors. The convulsions thus could serve as a good model for studying the actions of drugs on the central nervous system alpha-adrenoceptors.

Adrenergic alpha-Agonists↗
PubMed1991

Pain perception in decapitated rat brain.

The question of humaneness of decapitation per se has been considered. The time required for the oxygen tension in decapitated rat brain to decline to a level at which the brain becomes unconscious was estimated to be 2.7 sec. Assuming that decapitation is a powerful arousal stimulus and that the resulting EEG activation (low voltage, fast activity) indicates a conscious awareness of pain and distress the maximum time the pain and distress could be perceived would be 2.7 sec. Hence, decapitation of rats per se may be considered humane.

Animals↗
PubMed1992

Comparison of effects of decapitation and anesthesia on metabolic and hormonal parameters in Sprague-Dawley rats.

The modes of euthanasia by either anesthesia or by decapitation were compared by assessing several metabolic and hormonal parameters from plasma and hormone receptors from liver plasma membranes. Two different anesthetics were used. Compared to decapitation, euthanasia by anesthesia significantly increased plasma glucose and triglyceride levels but not plasma cholesterol. Plasma insulin was also significantly increased by anesthetics. No significant differences were observed in plasma glucagon levels or insulin and glucagon receptors from liver plasma membranes between rats euthanized by decapitation and anesthesia. Glucagon receptors were however, affected by dietary carbohydrates. It is concluded that in studies involving measurements of metabolic and hormonal parameters, the use of anesthesia is to be avoided for euthanasia and that decapitation should be the method of choice.

Anesthesia↗
PubMed1983

In vivo regional levels of PGE and thromboxane in mouse brain: effect of decapitation, focused microwave fixation, and indomethacin.

A focused microwave fixation technique was tested for use in determining basal PGE and thromboxane B2 levels of mouse brain. Focused microwave irradiation (3.5 Kw/0.4 sec) to the head of C3H mice produced basal values of PGE and TXB2 which were five-fold less than those in animals killed by decapitation. Indomethacin (10 mg/kg) pretreatment blocked the decapitation rise in PGE and TXB2 levels and gave values similar to focused microwave irradiation. Indomethacin pretreatment combined with microwave fixation did not reduce PG levels more than microwave treatment alone. When microwave fixation was used, there was no difference in regional (cerebral cortex, whole cerebellum, midbrain, hypothalamus) levels of either PGE or TXB2. However, PGE levels were significantly higher than TXB2 in all regions. After decapitation there was a greater increase in TXB2 than PGE. The cerebellum produced less PGE and TXB2 after decapitation compared to the other regions. Our results confirm the usefulness of the focused microwave irradiation technique for examining in vivo basal prostaglandin levels in mouse brain.

Animals↗
PubMed1997

A comparison between microwave irradiation and decapitation: basal levels of dynorphin and enkephalin and the effect of chronic morphine treatment on dynorphin peptides.

Opioid peptides were analysed in tissue extracts of various brain structures and the pituitary gland from rats sacrificed by microwave irradiation, and compared with peptide levels in tissue extracts from decapitated rats. Dynorphin A, dynorphin B and Leu-enkephalinArg6, derived from prodynorphin, and Met-enkephalinArg6Phe7 from proenkephalin, were measured. Basal immunoreactive levels of dynorphin A and B were consistently higher in extracts from microwave-irradiated rats, whereas in these extracts immunoreactive levels of Leu-enkephalinArg6, an endogenous metabolite of dynorphin peptides, were either lower than, the same as or higher than in decapitated rats. Immunoreactive levels of Met-enkephalinArg6Phe7 were higher in microwave-irradiated rats. Effects of morphine treatment on prodynorphin peptide levels were evaluated and compared with previous findings in decapitated rats. Dynorphin immunoreactive levels were higher in the nucleus accumbens and striatum of morphine-tolerant rats than in corresponding areas in saline-treated rats. These results indicate tissue-specific metabolism of prodynorphin peptides and show that metabolism of opioid peptides occurs during the dissection procedure after decapitation of the rat even though precautions are taken to minimize degradation.

Animals↗
PubMed2001

Rapid generation of 2-arachidonoylglycerol, an endogenous cannabinoid receptor ligand, in rat brain after decapitation.

Rat brain, frozen in liquid nitrogen immediately after decapitation, contains a substantial amount of 2-arachidonoylglycerol (0.34 nmol/g tissue), an endogenous cannabinoid receptor ligand. The level of 2-arachidonoylglycerol in the brain was rapidly augmented after decapitation, the peak being noted 30 s after decapitation (1.54 nmol/g tissue). Noticeably, there are two phases during the increase in the levels of 2-arachidonoylglycerol: a rapid transient increase and a subsequent gradual sustained increase, suggesting that at least two separate mechanisms are involved in the generation of 2-arachidonoylglycerol in the decapitated brain. Gradual sustained formation was also observed for other monoacylglycerols, (e.g. 2-palmitoylglycerol plus 2-oleoylglycerol and 2-cis-vaccenoylglycerol). Thus, it is important to minimize post-mortem changes to estimate the exact tissue levels of 2-arachidonoylglycerol as well as other monoacylglycerols in the brain.

Animals↗
PubMed1997

Relation between free fatty acid and acyl-CoA concentrations in rat brain following decapitation.

To ascertain effects of total ischemia on brain phospholipid metabolism, anesthetized rats were decapitated and unesterified fatty acids and long chain acyl-CoA concentrations were analyzed in brain after 3 or 15 min. Control brain was taken from rats that were microwaved. Fatty acids were quantitated by extraction, thin layer chromatography and gas chromatography. Long-chain acyl-CoAs were quantitated by solubilization, solid phase extraction with an oligonucleotide purification cartridge and HPLC. Unesterified fatty acid concentrations increased significantly after decapitation, most dramatically for arachidonic acid (76 fold at 15 min) followed by docosahexaenoic acid. Of the acyl-CoA molecular species only the concentration of arachidonoyl-CoA was increased at 3 min and 15 min after decapitation, by 3-4 fold compared with microwaved brain. The concentration of docosahexaenoyl-CoA fell whereas concentrations of the other acyl-CoAs were unchanged. The increase in arachidonoyl-CoA after decapitation indicates that reincorporation of arachidonic acid into membrane phospholipids is possible during ischemia, likely at the expense of docosahexaenoic acid.

Acyl Coenzyme A↗
PubMed2000

Decapitated and decaudated spermatozoa in man, and pathogenesis based on the ultrastructure.

The ultrastructure of decapitated tails and decaudated heads of ejaculated spermatozoa from an infertile man were investigated. The decaudated heads had the nucleus and acrosome, but neither the implantation fossa nor the basal plate were observed at the caudal pole of the nucleus. The nuclear membrane at this portion showed numerous nuclear pores. The decapitated tails contained the proximal centriole at the proximal end. In addition, most decapitated tails had segmented columns, outer coarse fibres, axoneme, mitochondrial sheath and fibrous sheath in the normal position. The ultrastructure reflects the high motility of the decapitated tails of the spermatozoa. Drastic abnormalities were found in the developing spermatids in the biopsied testes. In spermatids later than the Golgi phase, the pair of centrioles were floating in the cytoplasm of the spermatid, but the distal centriole elongated the flagellum. Neither the implantation fossa nor the basal plate were observed at the caudal pole of the nucleus. It is concluded that the tail might be separated from the head before or after completion of tail formation in spermatids. The explanation for why the proximal centriole failed to connect to the nucleus is unknown.

Adult↗
PubMed2003

Effects of high frequency electrical stunning and decapitation on early rigor development and meat quality of broiler breast meat.

Three independent trials were conducted to determine the effects of high frequency electrical stunning followed by decapitation on broiler breast meat rigor development and meat quality. All birds were stunned and half of the birds were killed using a conventional unilateral neck cut, half were killed by decapitation, and both groups were allowed to bleed for 90 s prior to scalding and picking. New York dressed carcasses were chilled in a static ice-water bath for 90 min and held at 2 degrees C prior to deboning. Breast fillets were removed from the carcasses at 2, 4, and 24 h postmortem. From the right breast fillet, R-values and pH were determined at time of deboning. The left fillet was wrapped in plastic and held for 24 h at 2 degrees C prior to determining lightness (L*), redness (a*), yellowness (b*), cook yield, and Allo-Kramer shear. Deboning time affected raw meat pH, R-value, cook loss, and shear value but had no effect on color. The breast meat from the decapitated birds had significantly higher pH values at 2 and 24 h postmortem than the conventionally killed birds. Other than for the effect on breast meat pH, decapitation had no effect on rigor development, R-value, meat color, or meat quality as measured by cooked-meat yield and Allo-Kramer shear.

Adenine Nucleotides↗
PubMed1994

Carbohydrate mobilization following shoot defoliation and decapitation in hybrid poplar.

The effects of shoot defoliation, decapitation, and disbudding on carbon mobilization were investigated in rooted cuttings of Populus maximowiczii x nigra L. 'MN9'. Ten days after complete shoot defoliation or decapitation, the stem starch concentration of treated plants declined to one-half that of intact plants, and there were similar or greater reductions in the concentrations of glucose, fructose, sucrose, galactose, and shikimic acid. Partial shoot defoliation (50%) and complete disbudding had no effect on stem starch concentration, but stem sucrose concentration was reduced in all treatments. Sucrose depletion preceded and may have induced other changes in the carbon status of plants subjected to leaf or shoot removal. Four days after shoot decapitation, the sucrose concentration of roots of treated plants was reduced to 25% of that of intact plants. However, the concentrations of fructose and glucose increased in the roots of treated plants and was followed by the accumulation of shikimic acid, salicyl alcohol, unknown compound A and salicin. The possible role of increased concentrations of root organic solutes in the water relations and regrowth process of decapitated plants is discussed.

Journal Article↗
PubMed2004

Features characteristic of homicide in cases of complete decapitation.

Four cases of complete decapitation connected to homicidal acts are presented. In 3 cases, decapitation was inflicted postmortem after killing the victim. The motives for decapitation were considered defensive, aggressive, and a possible combination of the 2 in one case each. In one case, decapitation was a vital injury and accounted for death. In this case, an offensive motive for mutilation was suspected. The combination of death scene findings and autopsy results will in most cases distinguish between homicidal and other modes of death.

Adult↗
PubMed2005

Auxin dynamics after decapitation are not correlated with the initial growth of axillary buds.

One of the first and most enduring roles identified for the plant hormone auxin is the mediation of apical dominance. Many reports have claimed that reduced stem indole-3-acetic acid (IAA) levels and/or reduced basipetal IAA transport directly or indirectly initiate bud growth in decapitated plants. We have tested whether auxin inhibits the initial stage of bud release, or subsequent stages, in garden pea (Pisum sativum) by providing a rigorous examination of the dynamics of auxin level, auxin transport, and axillary bud growth. We demonstrate that after decapitation, initial bud growth occurs prior to changes in IAA level or transport in surrounding stem tissue and is not prevented by an acropetal supply of exogenous auxin. We also show that auxin transport inhibitors cause a similar auxin depletion as decapitation, but do not stimulate bud growth within our experimental time-frame. These results indicate that decapitation may trigger initial bud growth via an auxin-independent mechanism. We propose that auxin operates after this initial stage, mediating apical dominance via autoregulation of buds that are already in transition toward sustained growth.

Flowers↗
PubMed1985

Gravitropic Responses of Partially Decapitated Corn Coleoptiles with and without Applied [C]Indoleacetic Acid.

The curvature of corn seedling (Zea mays L. Mo17 x B73) coleoptiles which had been half-decapitated and supplied with [(14)C]indoleacetic acid (IAA) (3.2 micromolar, 51 milliCuries per millimole) was determined during a 3-hour period of gravitational stimulation. Curvature of such half-decapitated coleoptiles was found to be similar in rate and extent to that of intact coleoptiles responding to gravity. Gravitational stimulation was accomplished by reorienting seedlings to a horizontal position, either up or down with respect to the removed half of the coleoptile tips.The first set of experiments involved placing aluminum foil barriers along one of the two cut surfaces to restrict the movement of IAA into tissues. The initiation and extent of curvature of these half-decapitated coleoptiles was dependent upon the orientation of the removed half-tip and the accompanying barrier. The distribution of radioactivity from [(14)C] IAA after 3 hours indicated that the specific lateral movement of label was also dependent upon orientation of the removed half-tip of the coleoptile. A specific movement to the lower side of approximately 14% of the total recovered radioactivity was found in coleoptiles in which the [(14)C]IAA was supplied across a transverse cut surface. In contrast, specific movement of only 4% was found for application across a longitudinal cut surface.A second series of experiments was conducted using 1.0 and 3.2 micromolar [(14)C]IAA (51 milliCuries per millimole) supplied to half-decapitated coleoptiles without inserted barriers. The 3.2 micromolar concentration adequately replaced the removed coleoptile half-tips in terms of straight growth, but it did not result in as much curvature as shown by coleoptiles of intact seedlings. The 1 micromolar concentration was not adequate to replace the removed half-tip in straight growth, but resulted in gravitropic curvature nearly as great as that produced by the higher concentration.The data presented here suggest that strong auxin gradients are not produced in response to gravity stimulation based on the recovered radioactivity from [(14)C]IAA. However, it is evident that auxin is required for the development of normal gravitropic responses. It is possible, therefore, that an important early role of this movement is not to cause a large stimulation of growth on the lower side but to decrease growth on the upper side of a gravitropically responding coleoptile.

Journal Article↗
PubMed2006

Look twice before you clamp: decapitation of an omphaloenteric duct. A case report.

OBJECTIVE: To report a case of accidental decapitation of a persistent omphaloenteric duct (POD) in congenital hernia of the umbilical cord in a newborn male. CASE PRESENTATION AND INTERVENTION: The newborn was transferred to an intensive care unit, where under closer inspection the diagnosis of an omphalocele was presumed. Surgical exploration at our Pediatric Surgical University Clinic revealed a clamped and decapitated POD in the umbilical cord. The decapitation had gone unnoticed due to severe asphyxia resulting from meconium aspiration encountered at the time of delivery. Using general anesthesia, the clamp was removed under sterile conditions. The decapitation of the POD in the herniated umbilical cord was confirmed at this time. The severed intestine was sutured and closed using 5-0 Vicryl sutures. The further course was uneventful. CONCLUSION: Herniation of the umbilical cord at the time of birth by intestinal loops or POD is rare, but caution should be taken by midwives before clamping in order to avoid the type of injury seen in this case.

Hernia, Umbilical↗
PubMed1975

Effect of ether inhalation by adrenalectomized pregnant rats on the adrenal corticosterone concentration in norma, decapitated, and encephalectomized fetuses.

The influence of decapitation or encephalectomy (total removal of the brain leaving the pituitary in place) on the adrenal corticosterone concentration of the 20-day-old rat fetus has been studied in normal pregnant rats, in adrenalectomized pregnant rats, and in adrenalectomized pregnant rats subjected to the stress conditions of inhalation of ether for 40 min. Decapitation or encephalectomy of the fetus always results in a drop in adrenal corticosterone concentration within 4 h which is prevented in 15 min by injecting 3.2 mU of hog ACTH into the decapitated fetus. In mothers adrenalectomized in order to avoid a negative feedback reaction of maternal corticosteroids on the fetal pituitary-adrenal system, ether inhalation causes an important rise in adrenal corticosterone concentration in normal fetuses but not in decapitated or encephalectomized ones. Thus ether, which crosses the placental barrier, is a stressor agent for the fetal rat.

Adrenal Cortex↗