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Pelligra T, Petrini D, Puccinelli C, Unti S, Citi S. Sonography of the pituitary gland in pet rats. Vet Radiol Ultrasound 2023; 64:1081-1089. [PMID: 37907397 DOI: 10.1111/vru.13308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 08/03/2023] [Accepted: 09/06/2023] [Indexed: 11/02/2023] Open
Abstract
Pituitary gland (PG) tumors are common in rats over the age of 2. CT and MRI can be difficult to apply in this species, whereas ultrasound is more feasible and useful. To our knowledge, there are no studies on PG ultrasound in rats. The aim of this prospective, analytical study was to evaluate the reliability of ultrasound in identifying PG, to define the ultrasound dimension of the gland in a group of rats with no evidence of pituitary diseases, and to examine its correlations with age, sex, and weight. After localizing the PG with an MRI study on one rat, the gland was identified in 21 rats by ultrasound by two sonographers using a ventral neck approach and a transversal scan with a linear probe. The gland appears as a hypoechoic oval structure with a thin hyperechoic margin. The rats (15 male and 6 female) ranged from 4 to 18 months in age (median 6 months) and from 270 to 640 g in weight (median 370 g). The median pituitary width was 3.96 mm (interquartile range 25-75%: 6-4.5 mm), and the median height was 1.48 mm (interquartile range 25-75%: 1.3-1.67 mm). There was no statistically significant correlation between PG size and rat weight, gender, or age. We believe that these ultrasound measurements could be useful for the diagnosis of pituitary disease, irrespective of whether neurological symptoms are present. We report a clinical case of a rat with a pituitary mass detected by ultrasound and CT.
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Affiliation(s)
- Tina Pelligra
- Department of Veterinary Sciences, Veterinary Teaching Hospital Mario Modenato, University of Pisa, Pisa, Italy
| | - Daniele Petrini
- Department of Veterinary Sciences, Veterinary Teaching Hospital Mario Modenato, University of Pisa, Pisa, Italy
| | - Caterina Puccinelli
- Department of Veterinary Sciences, Veterinary Teaching Hospital Mario Modenato, University of Pisa, Pisa, Italy
| | - Serena Unti
- Clinica Veterinaria Valdinievole, Monsummano Terme, Italy
| | - Simonetta Citi
- Department of Veterinary Sciences, Veterinary Teaching Hospital Mario Modenato, University of Pisa, Pisa, Italy
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Imaging Technologies for Cerebral Pharmacokinetic Studies: Progress and Perspectives. Biomedicines 2022; 10:biomedicines10102447. [PMID: 36289709 PMCID: PMC9598571 DOI: 10.3390/biomedicines10102447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/22/2022] [Accepted: 09/27/2022] [Indexed: 11/16/2022] Open
Abstract
Pharmacokinetic assessment of drug disposition processes in vivo is critical in predicting pharmacodynamics and toxicology to reduce the risk of inappropriate drug development. The blood–brain barrier (BBB), a special physiological structure in brain tissue, hinders the entry of targeted drugs into the central nervous system (CNS), making the drug concentrations in target tissue correlate poorly with the blood drug concentrations. Additionally, once non-CNS drugs act directly on the fragile and important brain tissue, they may produce extra-therapeutic effects that may impair CNS function. Thus, an intracerebral pharmacokinetic study was developed to reflect the disposition and course of action of drugs following intracerebral absorption. Through an increasing understanding of the fine structure in the brain and the rapid development of analytical techniques, cerebral pharmacokinetic techniques have developed into non-invasive imaging techniques. Through non-invasive imaging techniques, molecules can be tracked and visualized in the entire BBB, visualizing how they enter the BBB, allowing quantitative tools to be combined with the imaging system to derive reliable pharmacokinetic profiles. The advent of imaging-based pharmacokinetic techniques in the brain has made the field of intracerebral pharmacokinetics more complete and reliable, paving the way for elucidating the dynamics of drug action in the brain and predicting its course. The paper reviews the development and application of imaging technologies for cerebral pharmacokinetic study, represented by optical imaging, radiographic autoradiography, radionuclide imaging and mass spectrometry imaging, and objectively evaluates the advantages and limitations of these methods for predicting the pharmacodynamic and toxic effects of drugs in brain tissues.
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Tang F, Liu H, Zhang XJ, Zheng HH, Dai YM, Zheng LY, Yang WH, Du YY, Liu J. Evidence for Dopamine Abnormalities Following Acute Methamphetamine Exposure Assessed by Neuromelanin-Sensitive Magnetic Resonance Imaging. Front Aging Neurosci 2022; 14:865825. [PMID: 35707702 PMCID: PMC9190254 DOI: 10.3389/fnagi.2022.865825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 04/20/2022] [Indexed: 11/13/2022] Open
Abstract
BackgroundNeuromelanin-sensitive magnetic resonance imaging (NM-MRI) is a newly developed MRI technique that provides a non-invasive way to indirectly measure of dopamine (DA) function. This study aimed to determine NM concentrations in brain regions following acute methamphetamine (MA) administration using NM-MRI and to explore whether NM-MRI can be used as a biomarker of DA function in non-neurodegenerative diseases.MethodsBaseline NM-MRI, T1-weighted and T2-weighted images were acquired from 27 rats before drug/placebo injection. The control group (n = 11) received acute placebo (Normal saline), while the experimental group (n = 16) received acute MA. NM-MRI scans were performed 5, 30, 60 and 90 min after injection. Regions of interest (ROIs), including the caudate putamen (CP), nucleus accumbens (NAc), hippocampus (HIP), substantia nigra (SN) and crus cerebri (CC), were manually drawn by an experienced radiologist. NM-MRI signal intensity in five brain regions at different time points (baseline and 5, 30, 60, and 90 min) were analyzed.ResultsIn both the control and experimental groups, at each time point (baseline and 5, 30, 60, and 90 min), the SN exhibited significantly higher NM-MRI signal intensity than the other brain regions (P < 0.05). In addition, acute MA administration resulted in a continuous upward trend in NM-MRI signal intensity in each brain region over time. However, there was no such trend over time in the control group. The NM-MRI signal intensity of SN in the experimental group was significantly higher at the 60 and 90 min compared with that in the control group (P values were 0.042 and 0.042 respectively). Within experimental group, the NM-MRI signal intensity of SN was significantly higher at the 60 and 90 min compared with that before MA administration (P values were 0.023 and 0.011 respectively). Increased amplitudes and rates of NM-MRI signal intensity were higher in the SN than in other brain regions after MA administration.ConclusionOur results indicated that NM was mainly deposited in the SN, and the conversion of DA to NM was most significant in the SN after acute MA exposure. Increased DA release induced by acute MA exposure may lead to increased accumulation of NM in multiple brain regions that can be revealed by NM-MRI. NM-MRI may serve as a powerful imaging tool that could have diverse research and clinical applications for detecting pathological changes in drug addiction and related non-neurodegenerative diseases.
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Affiliation(s)
- Fei Tang
- Department of Radiology, Second Xiangya Hospital of Central South University, Changsha, China
| | - Hui Liu
- Department of Radiology, Second Xiangya Hospital of Central South University, Changsha, China
| | - Xiao Jie Zhang
- Department of Radiology, Second Xiangya Hospital of Central South University, Changsha, China
| | - Hui Hui Zheng
- Department of Radiology, Second Xiangya Hospital of Central South University, Changsha, China
| | - Yong Ming Dai
- MR Collaboration, Central Research Institute, United Imaging Healthcare, Shanghai, China
| | - Li Yun Zheng
- MR Collaboration, Central Research Institute, United Imaging Healthcare, Shanghai, China
| | - Wen Han Yang
- Department of Radiology, Second Xiangya Hospital of Central South University, Changsha, China
| | - Yan Yao Du
- Department of Radiology, Second Xiangya Hospital of Central South University, Changsha, China
| | - Jun Liu
- Department of Radiology, Second Xiangya Hospital of Central South University, Changsha, China
- *Correspondence: Jun Liu,
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