Introduction: Effective and safe anesthesia for rodents has long been a leading concern among biomedical researchers. Intraperitoneal injection constitutes an alternative to inhalant anesthesia.

Purpose: The aim of this study was to identify a safe, reliable, and effective anesthesia and postoperative analgesia protocol for laboratory rats exposed to painful procedures.

Material and methods: Twenty-seven female Wistar rats in an ongoing study that required surgery were randomized into groups for three different intraperitoneal anesthesia protocols and three different analgesia regimens. The anesthesia groups were (1) medetomidine + ketamine (MK), (2) ketamine + xylacine (KX), and (3) fentanyl + medetomidine (FM). Three analgesia groups were equally distributed among the anesthesia groups: (1) local mepivacaine + oral ibuprofen (MI), (2) oral tramadol + oral ibuprofen (TI), and (3) local tramadol + oral tramadol + oral ibuprofen (TTI). A core was assigned to measure anesthesia (0-3) and analgesia (0-2) effectiveness; the lower the score, the more effective the treatment.

Results: The mean MK score was 0.44 versus 2.00 for FM and 2.33 for KX. Mean score for analgesia on the first postoperative day was TTI (4.66) TI (9.13), and MI (10.14). Mean score 48 hours after surgery was TTI (3.4), TI (6.71), and MI (9.5). These differences were statistically significant.

Conclusion: MK was shown to be a reliable, safe, and effective method of anesthesia. The TTI analgesia regimen is strongly recommended in light of these results.

The specific name velunensis is established to encompass porcupine remains ( Hystrix Linnæus, 1758) recovered from the Pliocene site of Węże 1 in southern Poland. The studied specimen was previously assigned either to H. primigenia (Wagner, 1848) or H. depereti Sen, 2001, however it can be distinguished from these species and other fossil Hystricidae by its distinct occlusal morphology, most importantly the presence of an anterolingual flexus dissecting the anteroloph of P4. Hystrix velunensis sp. nov. was probably closely related to H. primigenia and H. depereti. A previously undescribed specimen from the nearby site of Węże 2 most probably belongs to H. refossa Gervais, 1852b, which would be the first known occurrence of this species in Poland.

Fumonisins are highly toxic metabolites produced by Fusarium proliferatum and Fusarium verticillioides. Little is known about the effects of a chronic low level of fumonisins on intestinal structure and innervation in monogastric animals, even though the intestine is the first organ exposed to fumonisins. The influence of the most prevalent strains of fumonisins, FB1 and FB2, on intestinal and liver morphology, the enteric nervous system and intestinal epithelial cell prolif- eration was investigated in an experimental rat model of fumonisin intoxication. Adolescent (5-weeks-old), male Wistar rats were randomly divided into a control group (C group) not treated with fumonisins or intoxicated with fumonisins (FB group). FB1 together with FB2 were daily administered intragastrically at a dose of 90 mg/kg body weight for 21 days. The damaging effect was assessed by determination of the activity of ALAT and AspAT. Samples from the small intes- tine and liver were taken and blood samples were collected to determine the activity of gamma-glutamyl transferase (GGT) and amylase. The exposure to FBs resulted in histopathological degenerative alterations in hepatocytes, including mild vacuolar degeneration and ballooning. FB exposure was also toxic in the duodenum and jejunum, where significant changes in morphology, cell proliferation, collagen wall fibres and innervation were observed. Taken together, the results obtained strengthen the hypothesis that chronic exposure to FBs could induce intestinal damage, including damage to the enteric nervous system and may have consequences for general health.